ANNUALREPORT2 O 2 O
Vol.1: HighlightEditorial Board (April 2021 – March 2022)

Pranab SAHA (Accelerator Division)

Takayuki YAMAZAKI (Materials and Life Science Division)

Yoshiaki FUJII (Particle and Nuclear Physics Division)

Makoto YOSHIDA (Particle and Nuclear Physics Division)

Shigeru SAITO (Transmutation Division)

Hajime NAKAMURA (Safety Division)

Shinji NAMIKI (Users Office Team)

Naomi EBISAWA (Public Relations Section)

Cover photographs
Photograph ① : Inside of a floral shaped beam duct
Image credit: Taihei ADACHI

Photograph ② : Beautiful view from the downstream
Image credit: Junko KITAGISHI

Photograph ③ : Radio-frequency quadruple linac, RFQ
Image credit: Masashi OTANIJ-PARC Annual Report 2020
Contents
Preface……………………………………………………………………………………………………………… 1
Accelerators………………………………………………………………………………………………………… 3
Overview of the Accelerator…………………………………………………………………………………… 3
Linac ………………………………………………………………………………………………………… 6
RCS…………………………………………………………………………………………………………… 9
MR………………………………………………………………………………………………………… 12
Materials and Life Science Experimental Facility………………………………………………………………… 15
Overview…………………………………………………………………………………………………… 15
Neutron Source Section…………………………………………………………………………………… 16
Neutron Science Section…………………………………………………………………………………… 17
Neutron Device…………………………………………………………………………………………… 18
Muon Section……………………………………………………………………………………………… 19
Technology Development Section………………………………………………………………………… 21
Particle and Nuclear Physics……………………………………………………………………………………… 23
Neutrino Experiment……………………………………………………………………………………… 23
Hadron Experimental Facility……………………………………………………………………………… 24
Strangeness / Hadron Physics Experiments ………………………………………………………………… 25
Kaon Decay Experiment…………………………………………………………………………………… 25
Muon Experiments………………………………………………………………………………………… 25
Theory group……………………………………………………………………………………………… 26
Technical Support Groups………………………………………………………………………………… 26— Research Highlight — The JSNS2 experiment gets started!!…………………………………………… 27— Research Highlight —First determination of the binding energy of the Ξ hyperon in the Ξ hypernucleus……………………… 29— Research Highlight — Updated results from KOTO……………………………………………………… 31
Cryogenics Section ……………………………………………………………………………………………… 33
Overview…………………………………………………………………………………………………… 33
Cryogen Supply and Technical Support…………………………………………………………………… 34
Superconducting Magnet System for T2K………………………………………………………………… 34
Superconducting Magnet Systems at the MLF…………………………………………………………… 35
Superconducting Magnet Systems at the HEF …………………………………………………………… 35
R&D for the Future Projects at J-PARC……………………………………………………………………… 36

Information System……………………………………………………………………………………………… 37
Overview…………………………………………………………………………………………………… 37
Status of Networking……………………………………………………………………………………… 37
Internet Connection Services for Visitors and Public Users of J-PARC……………………………………… 39
Status of Computing ……………………………………………………………………………………… 40
Transmutation Studies…………………………………………………………………………………………… 43
Overview…………………………………………………………………………………………………… 43
Research and development ……………………………………………………………………………… 44
MA Irradiation Experiments ………………………………………………………………………………… 47
International and Domestic Cooperation ………………………………………………………………… 48
Safety ……………………………………………………………………………………………………………… 49
Safety……………………………………………………………………………………………………… 49
User Service ……………………………………………………………………………………………………… 53
Users Office (UO)…………………………………………………………………………………………… 54
User Statistics……………………………………………………………………………………………… 56
MLF Proposals Summary - FY2020………………………………………………………………………… 57
J-PARC PAC Approval Summary for the 2020 Rounds……………………………………………………… 59
Organization and Committees…………………………………………………………………………………… 61
Organization Structure……………………………………………………………………………………… 62
Members of the Committees Organized for J-PARC………………………………………………………… 63
Main Parameters ………………………………………………………………………………………………… 69
Events ……………………………………………………………………………………………………………… 71
Events……………………………………………………………………………………………………… 71
Publications……………………………………………………………………………………………………… 77
Publications in Periodical Journals………………………………………………………………………… 78
Conference Reports and Books…………………………………………………………………………… 86
KEK Reports………………………………………………………………………………………………… 93
JAEA Reports……………………………………………………………………………………………… 94
Others……………………………………………………………………………………………………… 94

J-PARC Annual Report 2020

Preface1

Preface
In Japanese fiscal year (JFY) 2020, from April 2020 through March 2021, we
made significant progress at J-PARC on many fronts and a few of our achievements
are covered below.
Early in JFY2020, we faced an unexperienced and difficult situation as the firstpeak of COVID spread in Japan. Travel from abroad stopped, and domestic travel
was also severely limited. In that situation, the MLF beam had to be suspendedthon April 20 to secure the safety of users and our staffs. After implementingth
preventive measures, we were able to restart the user beam on May 15 .
We achieved a 600-kW stable beam operation for the MLF. The total time
provided for the user beam was about 3300 hrs (137 days) with the very highPreface

J-PARC Annual Report 2020

2

availability of ~92 %. The Main Ring achieved a stable operation at 50 kW and
510 kW for hadron experiments and neutrino experiments, respectively. In
JFY2020, 8 days of neutrino beams and 22 days of hadron beams were provided.
In the MLF, a new liquid mercury target with improved design for higher beam
power was developed, installed, and successfully operated. Also, a test operation
at ~1 MW (930 kW) beam power was successfully conducted for 36.5 hrs, which
was also a major milestone toward realizing 1 MW stable user operation.
The neutrino group has established significant constraints on the CP phase.
The hadron experimental facility is now equipped with a new target system,
which can handle more beam power, and a new beamline, B-Line, to receive a
primary proton beam.
In this volume, we report the progress made at J-PARC in JFY2020.

On behalf of the J-PARC staff members,
Director of J-PARC Center

Takashi KOBAYASHI

Accelerators

Overview of the Accelerator
The J-PARC accelerator complex consists of a 400
MeV linac, a 3 GeV Rapid Cycling Synchrotron (RCS)
and a Main Ring Synchrotron (MR, 30 GeV). The proton
beam from the RCS is delivered to the Materials andLife Science Experimental Facility (MLF) for neutron andmuon experiments and is also injected into the MR. The
MR has two beam extraction modes: fast extraction (FX)
mode for the Neutrino experimental facility (NU) andslow extraction (SX) mode for the Hadron experimental
facility (HD).
The operation in JFY2020 is illustrated in Fig. 1. The
topics related to the beam operation are as follows:(1) Operation for the MLF
The beam operation Run#84 was started in January
and continued until April 20 when it was stopped due

Fig. 1. Accelerator operation in JFY2020 (covers partially the end of JFY2019).

Accelerators

J-PARC Annual Report 20204
to the COVID-19 breakout. We also had a scheduled outage from May 1 to 10. The user operation was resumed
from May 15 only for the MLF at a beam power of 500
kW, because the licensing for a new target and a newbeam line in the HD was delayed by the authorities andthe beam operation was postponed. The beam power
to the MLF was increased to 600 kW from May 18. The
user program was carried out as scheduled until June
27, also, an operation with the designed beam powerof 1 MW was successfully executed from June 25 to 27.
The user operation for the MLF ended on June 27 followed by a six-day accelerator study before the summer
shutdown.
After the summer shutdown, the user program of
the MLF restarted on December 1.
The neutron production target of the MLF was
replaced during the summer shutdown. Due to thedelay of the target-related work, the beam tuning andthe user operation were postponed until the end of
November, a two-week delay from the original schedule. The beam power for the user operation was 600 kW,
the same as before the summer shutdown.
We had the usual shutdown period for about 2
weeks from the end of December until the beginning ofJanuary. The linac tuning started on January 7 followedby the RCS. The MLF user program started on January
12 and continued until the end of March as scheduled.

February 7. The HD user operation was resumed on
February 8. The beam power was gradually increased to
60 kW, which was the maximum beam power for the hadron user operation in J-PARC. The user program went onsmoothly until February 28, but the ESS#1 (Electrostatic
Septum #1) had a failure due to unexpected stoppageof few main quadrupole and sextupole magnets. The
quadrupole magnets on three straight sections went
down unexpectedly due to the accidental malfunctionof the 22 kV circuit breaker causing a large deviation of
the circulating beam towards the ESS#1. The deviation
resulted in a large beam loss and breakage of some of
the ESS#1 ribbons. The broken ribbons caused a shortcircuit failure of the ESS#1. Most of the lost beam spreadthroughout the Main Ring, and only a small fraction of
the beam was extracted to the hadron target (no temperature rise was observed on the target). The broken
ESS was removed from the beam line and a vacuum
pipe was installed instead. Meanwhile, we started toprepare a spare ESS. The MR operation was changed forthe neutrino user operation. We investigated the causeof malfunction of the circuit breaker. After identifying
the cause and taking countermeasures, we restarted
the hadron user operation. The neutrino user operation
was restarted on March 8 at a beam power of 510 kW,
and stopped on March 19 to prepare for the restart of
the hadron user operation, which began on March 27.

(2) Operation of the MR for the Neutrino Experiment (FXmode) and Hadron Experiment (SX mode)
The beam delivery to the Hadron experimental
facility (HD) was started at a lower beam power on May
28. After fine tuning of the MR, we delivered beam ataround 51 kW, a level similar to the previous operation.
The HD user program was executed on June 25 and 26
at a beam power of around 51 kW, and a one-day beam
study was carried out after the HD user program. The
MR operation was completed on June 27 before thesummer shutdown.
The beam studies at the MR after the summer
maintenance started on December 10, and the beam
delivery to the Hadron experimental facility (HD)resumed at beam power of 20 kW on December 14.
After fine tuning of the MR, we delivered a beam ataround 55 kW, the highest beam power for the HD user
operation at the time.
However, due to the cooling water failure in the
hadron facility, the HD user program was postponed
until mid-February. The schedule was changed to installa new power supply and that work continued until

The operation statistics for JFY2020 (from April
2020 to March 2021) are shown in Table 1 and Fig. 2. The
total operation time, which included the shift leaderson duty time at the control room, the startup and the RF
conditioning, was 4,632 hours. The net user operation
hours and the beam availability rate for each experimental facility were as follows: 3,138 hours (95.3%) for
the MLF; 134 hours (69.8%) for NU; and 344 hours (66%)
for HD. These statistics show that the linac and the RCS
operated with high availabilities. The cause of the lower
availability for the NU operation was due to the trouble
in the power supply of the injection magnet and also toa problem during the HD operation caused by the ESS
ribbon failure in March 2021.
The downtime by components is shown in Fig. 3.
There were several causes of the downtime. For the
linac, HVDC and SDTL are still dominant. However,the cause of the stoppage incidents in SDTL was not
the SDTL cavity, most of them are caused by the malfunction of LLRF. LLRF troubles were also counted astroubles in each cavity. The RCS outage was mainly due

J-PARC Annual Report 2020

Accelerators

5
to the RF and the cooling water. The RF outage was notdue to the cavity, but to the failure of the capacitor andthe end of life of the vacuum tube in the amplifier. Mostof the RCS stops occurred during the 1-MW operation inlate June. The MR had only one serious downtime event,which was the trouble of the ESS#1 in the “Slow ext.”
category. There was more than 100 hours downtime

in the 3NBT caused by the trouble in the cooling water
system, but it did not stop the user operation as thetrouble occurred during the scheduled beam tuning
period. These improved items, major downtime causes,
achievements and history of the beam operation are
described in the following chapters.

Table 1. Operation statistics in hours for JFY2020. Figures in the parentheses in trouble columns show the loss time contributions as percentage.
Facility

User Time(hours)Trouble, Acc.only(hours)Trouble, Faculty only
(hours)Net Time(hours)Availability, Total
(%)

MLF

3,291

143 (4.4%)

10 (0.3%)

3,138

95.3

Neutrino(FX)

192

45 (23.4%)

13 (6.8%)

134

69.8

Hadron(SX)

520

161 (31.0%)

15 (2.9%)

344

66.1

For MLF users

For MR users

Fig. 2. Operation statistics for JFY2020. The total operation time was 4,632 hours.

Fig. 3. Downtime by components in JFY2020.

Accelerators

J-PARC Annual Report 2020

6

Linac

Fig. X-1. Operation history of the ion source in JFY2020.

Overview
The J-PARC linac has been operated with a nominal
peak beam current of 50 mA. High availability of approximately more than 95% (to the MLF) was achieved
during JFY2020 at the linac, the same as in JFY2019.
Three 10-hour long beam stop events occurred due tothe replacement of the klystron and the failure of the
klystron peripheral devices. Beam studies have been
conducted to resolve some issues, such as the beamloss mitigation, confirmation of feasibility for the further upgrade plan, and so on.
Accelerator components status
The operation history of the ion source in JFY2020
is shown in Fig. X-1. Presently, the ion source is being
operated with a beam current of 60 mA for the user
operation. At the end of RUN#85, the ion source
extracted stable 72 mA beams for high-intensity beamstudies at the linac. In RUN#84, a continuous operationof 2,445 hours with 60 mA was achieved, which was
about 605 hours longer than the previous record. We
skipped the replacement work of the ion source in thiswinter shutdown and took the challenge to achieve acontinuous operation for more than 3,500 hours by theend of April 2021.
Figure X-2 shows the time variation of number of
RFQ trips. The RFQ trip rate was approximately 10 times
per day during the 25 Hz (MLF) beam operation in
JFY2020, which is almost the same as before. To reducethe downtime of the linac due to the RFQ trip, we
installed a new restart system for the RFQ. Previously,

when the RFQ trip occurred, it took about 1 minute toresume the beam operation because the operator had
to reset the MPS (machine protection system) manually.
The new system can skip the MPS process and resume
the beam operation automatically with the next macropulse (40 msec), therefore, the resume time can besignificantly reduced from 1 minute to 40 msec. The
new system saves about 10 minutes of no-beam time ina day, which can be expected to lead to a 1% improvement in the availability of the J-PARC accelerator.

Fig. X-2. Time variation of the number of RFQ RF-trips.

After the Great East Japan Earthquake in 2011, we
could not operate with the design rf power in some
SDTL cavities due to the multipactor effect. By wiping the inner surface of the cavity with acetone, themultipactor region disappeared completely, except
in the SDTL05A. Therefore, the input rf power of thisJ-PARC Annual Report 2020

Accelerators

7
cavity and neighboring ones were slightly shifted tosatisfy the beam quality while avoiding the multipactor
region. Although this situation does not immediately
affect the operation, we tried wiping with a different
substance, diluted sulfuric acid, in the summer of 2020.
As a result, the region did not disappear completely, but
the rate of deterioration during the operation time wasclearly slower than that with acetone. We will continue
to observe the progress and verify the cleaning effect.
The operation of the ACS cavities was more stable
than the other accelerator sections. The number of tripsof all the ACS cavities was less than once per day.
RF system status
We have been handling two types of klystrons, a
324-MHz klystron and a 972-MHz one. The operation
times of the klystrons as of March 2021 are shown in
Fig. X-3. Eight out of twenty 324-MHz klystrons reachedmore than 75,000 hours of operation, which has been
the entire period since the linac operation was started.
Most of the 972-MHz klystrons reached more than
45,000 hours of operation.
In JFY2020, we suspended the beam operation
once to replace a failed klystron (for SDTL09). The klystron failed due to a defective waveguide connection
flange. The defect was caused by arching that occurredin a very small gap between the klystron and theFig. X-3. The operation time of the 324-MHz klystron (top)and 972-MHz klystron (bottom) as of March 2021.

waveguide connection flange. Although there was noproblem with the performance of the klystron itself, wedecided to replace it because the repair of the flange onsite would have taken a lot of time.
Two failures in the klystron peripheral device
stopped the beam operation for about 10 hours. The
first failure was the malfunction of a power supply for a
klystron main coil. The malfunction was caused by temperature rise inside the power supply housing after acooling fan stopped. The second one was caused by adefect of a high voltage cable connecting the klystronand an anode modulator. It was restored by replacing
the cable, but the beam was stopped for a long time
because it took time to investigate the cause.
Beam monitor development
We are working to improve the beam quality of thelinac by tuning the beam in a MEBT1 (medium energy
beam transport1 located between the RFQ and theDTL). In the MEBT1, the beam energy is as low as 3 MeV,
so the heat load on the beam irradiation portion of thebeam monitor is very large, and as a result, the monitor
has often failed. Therefore, we needed to develop newmonitors with higher thermal load tolerance.
We developed a modified wire scanner monitor (WSM) based on the carbon nanotube (CNT) wire,
which has high tensile strength and electric conductivity. After confirming that the CNT-WSM obtained almost
the same result as the conventional WSM, all the WSMs
at the MEBT1 were replaced with the CNT type in thesummer of 2020.
We also developed a new bunch shape monitor(BSM) which can measure a longitudinal beam profile.
The measurement of the profile at the MEBT1 was difficult with the conventional BSM using a tungsten wire
as a secondary-electron production target due to thelimitation of the thermal-fatigue damage. Therefore, ahighly oriented pyrolytic graphite (HOPG), which has
high thermal load tolerance, was adopted as the target.
As a result of the off-line beam test, it was confirmedthat the new BSM was able to withstand the 3-MeV
beam sufficiently and worked fine to measure thebunch shape as did the conventional type. The new
BSM was installed in the MEBT1 in the summer of 2020,
and we utilize it as a beam tuning tool.
Beam study
The beam studies have been conducted at theinterval of the user operation and before and after the
long-term shutdown.

Accelerators

J-PARC Annual Report 2020

8
High residual radiation at DTL1 due to the beam loss
was detected after the 50-mA operation commenced in
2018. Using a smooth local focusing correction schemewith the current of the DTQ (drift tube quadrupole)magnets set to maximum 60% higher than the design
value, the beam loss was significantly decreased. After
further detailed investigation, we confirmed that 30%
correction could be sufficient to remove the beam loss.
At the ACS section, the dominant source of thebeam loss was found to be the IBSt (intra-beam stripping) in the H- beam. Because the IBSt can be only
mitigated by beam optics, some optics with a different
temperature ratio between transverse and longitudinalplanes (Tx/Tz) were examined (The optics of Tx/Tz=1.0 is
the J-PARC linac baseline design based on the equipartitioning setting). Since it was confirmed that the beamloss at the case of Tx/Tz=0.7 was reduced by 40% compared to the Tx/Tz=1.0, the operation with Tx/Tz=0.7
was commenced from April 2019. Two years havepassed since we commenced operation under the newcondition, and the linac has been operated stably without any problems due to the new condition. In order tostudy the possibility of further reduction of the beamloss, we started beam test with Tx/Tz of 0.5 and 0.3.
We are considering a further upgrade plan toincrease the RCS beam power to 1.5 MW. To realize theupgrade plan, the beam current and the beam pulse
length must increase to approximately 60 mA and 600
μs respectively. We successfully extracted 60-mA and
600-s beam from the linac in July 2019. Although thebeam current and the pulse length were satisfying

the upgrade requirement, the linac output emittance
was large. To improve the emittance, fine tuning of
the beam parameter at the MEBT1 and re-matching in
the three matching sections of the linac (SDTL, MEBT2,
L3BT) were performed. As a result, a reduction of thebeam loss of about 10% was achieved.
We also conducted the beam loss reduction study
for the 60-mA operation. The result is shown in Fig.
X-4. In this study, we applied a transverse-longitudinal
matching, Tx/Tz = 0.7. The beam loss was mitigated atmost of the BLM position, where a total reduction of
32% was achieved as compared to that with a Tx/Tz=1.0
optics. However, there are three “abnormal” points left
as shown by the red circles. Further optimization of theTx/Tz ratio is planned to improve the result in a near
future study.

Loss mitigation lattice applied for 60mA

Tx,y/Tz=1.0

Tx,y/Tz=0.7

Fig. X-4. D istribution of the beam loss signal at the ACS section in case of Tx/Tz=1.0 and 0.7.

Accelerators

J-PARC Annual Report 2020

9RCS
Operational status
At the beginning of JFY2020, RCS delivered a 500kW proton beam for the neutron users in the MLF.
Unfortunately, the whole operation at the J-PARC
accelerator was suspended for about three weeks frommid-April due to the first pandemic of COVID-19 inJapan. The beam operation was resumed by increasing
the beam power to 600 kW and continued at that level
during JFY2020. Just before the summer shutdown
period, we tried a two-day continuous operation at
1-MW beam power for the MLF. Meanwhile, the number of the protons for MR was 6.7e13 particles per pulse
which corresponds to 515-kW output beam power of
MR. Figure 1 shows the change in the RCS output beam
power with respect to time.
This year, the operational status of the RCS was
almost stable. One incident occurred at the coolingwater pump of the 3NBT line. In mid-January 2021, a
shaft wear sensor for a bearing motor in the pump senta warning signal. We investigated the pump and foundthe sensor gave a wrong alert. We spent about one
week to recover from this incident.
The availability of the RCS is summarized in the
Table 1. The operation time for the MLF over the year

was approximately 3291 h, excluding the commissioning time, and the downtime was approximately 38 h.
The availability for the MLF, estimated by these values,
was 98.9%. For the Neutrino and Hadron users, theavailability of RCS was almost the same as in the MLF
case, the value being around 99%.
Table 1. Summary of the RCS availability.
Facility

User time(h:m)

Trouble in
RCS (h)Availability of
RCS (%)

MLF

3290:58

37:45

98.9

Neutrino

192:260:16

99.9

Hadron511:56

9:37

98.2

Maintenance and improvements• Radiation shielding installation around the injection
chamberAt the recent operational condition, the major
radio-activated point in the RCS is at the injection foilchamber. The residual dose value on the surface of theFig. 1. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Accelerators

J-PARC Annual Report 2020

10

1-MW demonstration
We attempted a two-day continuous user operation
to the MLF with 1-MW beam power at the end of June
2020. During the 1-MW operation, two failures occurredat the capacitor and vacuum tube in the final stage
amplifier of the RF cavity immediately after the 1-MW

Fig. 2. Injection point of the RCS before (top) and after (bottom) installation of the temporary shielding.

operation started. The recovery took approximately 12h; thus, the 1-MW operation time was reduced to 36 h.
We hypothesize that these failures were mainly causedby age-related deterioration, and the 1 MW beam
power did not affect the deteriorations directly.
This 1-MW demonstration showed a serious issue
that prevented a stable operation. We found thatwhen the outside temperature increases, the supply

Dose [uSv/h]

injection foil chamber was about 10 mSv/h at 4 h after
the halt of the beam operation, and the worker dosearound the injection point was quite high compared tothat in other regions. Therefore, we considered countermeasures for the radiation around the injection
region to reduce the worker dose at the high-intensity
operation.
First, we considered changing the shape and location of the magnets near the injection point to installa permanent radiation shielding around the injection
foil chamber. However, Monte Carlo simulation results
indicated that a permanent radiation shielding would
not reduce effectively the dose due to the residual activation because the radiation shielding itself would be
activated.
Therefore, we changed our policy to prepare a temporary shielding under the present configuration. Two
10-ton cranes were present in the accelerator tunnel,
and we moved and installed the temporary shielding
using those cranes. However, since the original baseof the foil chamber could not withstand the weight of
the temporary shielding, we needed to replace it witha new one. We designed a new base and temporary
shielding that can be easily attached using a crane. The
replacement work on the new base was carried out inthe summer shutdown period of 2020. Since a large
amount of radiation exposure was expected during thisoperation, a detailed work plan was prepared. The work
plan sheet included a work process, working conditions,job descriptions, positions of the workers, and dose rate
for each position. We evaluated the worker doses using
these data and controlled the personnel doses so thatthey would not be concentrated on one person. Thanks
to these preparations, the work was completed with thedoses of all workers below the expected value. Picturesof the injection point before and after the installation of
the shielding are shown in Fig. 2.
Finally, we investigated the effect of this new temporary shielding just after the user operation. Figure 3
shows the measurement results of the dose rate near
the foil chamber. The result showed that the residual
dose rate was significantly reduced by the shielding.

140

Without shielding

90
With shielding

40
-10

0

100

200

300

Distance from chamber [mm]Fig. 3. Measured residual dose rate near the foil chamber.

J-PARC Annual Report 2020

Accelerators

11
temperature of the cooling water becomes uncontrollable and also increases. This induces the temperatureinterlock of the vacuum tube in the RF final stage
amplifier. We need to improve the RF and/or the cooling water system to establish a stable 1-MW operation
during summer.
After the1-MW user operation, we measured theresidual dose values around the accelerator components and found that those were low enough toaccept and the same as the results of the previous year.
Considering the beam loss, it is still possible to deliver
1-MW beam power to users. Figure 4 shows the residual dose values in the RCS after the 600-kW and 1-MW
operations. The dose values are almost proportional tothe beam power.

Summary
RCS has almost achieved a continuous, stable user
operation. In JFY2020, it delivers a 5.1e13 ppp (600 kW)
beam to the MLF and 6.7e13 ppp (corresponding to a
515-kW beam of MR) beam to the MR. These values will
be increased steadily with careful monitoring of theneutron target status and beam loss.
We attempted a 1-MW continuous operation at
the end of June 2020. The 1-MW continuous operation revealed the problem of poor cooling water
performance. To establish a stable 1-MW operation inall seasons, we have to consider improving the RF andthe cooling water systems. We continue the study toestablish a more stable condition.

Fig. 4. Residual dose distribution in the RCS after 600-kW and 1-MW user operations.

Accelerators

J-PARC Annual Report 2020

12

MR
Overview
The Main Ring synchrotron (MR) is a high-power
proton accelerator for experimental users of elementary-particle physics and nuclear physics. Proton beamsof 3 GeV from RCS are injected in MR and accelerated to
30 GeV. The beams are delivered either to the hadronexperimental hall with slow extraction (SX) mode or to
the neutrino facility with fast extraction (FX) mode. For
the SX operation the beam is extracted in about 2 s of
debunched beam spill with the cycle of 5.2 s. The beam
spill is delivered to the hadron experimental hall to produce various secondary particles for the experimental
users. For the FX operation the beam is extracted in one
turn with the cycle of 2.48 s. The beam is delivered to
the neutrino facility for the T2K long baseline neutrino
experiment.
Efforts have been made to increase the beam
power for the SX mode. The main concern has been the
beam instability, that has resulted in beam losses at the
debunching process before the extraction. The beam
power has been upgraded to 60 kW with suppressionof the instability. For the FX mode, the beam power was
510 kW. Minimizing the beam losses and the localization are issues to be resolved.
Main magnet power supplies were constructed forthe beam power upgrade. The test operation for the
faster cycling was successful. Second harmonic RF cavities were installed during the summer shutdown. The
FX septum magnet was tested for the faster cycling.
Some of the upgrade works should be completed by
the end of JFY2021 and the faster cycle operation of
1.32 s for FX is planned for JFY2022.
SX-mode operation
The beam power of the SX operation was 51 kW in
JFY2019 because of the power limit of the hadron production target. Since the target was upgraded for the
beam power of 95 kW, the MR operation was optimized
for the higher beam power. The most serious issue was
the transverse beam instability evoked by longitudinalmicrostructure during the debunching process that
resulted in beam losses. It was mitigated with a RFphase offset at injection. The longitudinal beam emittance became large after dilution, and was effective forthe instability suppression up to 51 kW. For a higher
power beam, the instability was observed with only thephase offset injection and a further mitigation scheme
was necessary. A new scheme of the RF voltage ramp

down for debunch was discovered to be effective. The
RF voltage was ramped down from the acceleration
voltage of 256 kV to ~20 kV at the end of the acceleration, and after 80 ms it was ramped down to 0 kV for
debunch. Longitudinal emittance became larger andthe instability was significantly suppressed. The beam
power of 60 kW was achieved for the user operation.
The beam availability for the hadron hall was 66.1%
in JFY2020. Troubles occurred on the power supplies of
the 3-50BT magnets, SX resonance sextupole magnets
and SX septum magnets. They may have been caused
by deterioration over time, because the components
are 15 years old and some even older. The importanceof maintenance to achieve better beam availability isrecognized more and more. For instance, we found adamaged gate circuit board in the 3-50BT magnet
power supply. Besides, the room temperature at thepower supply is inappropriately high. The environment
in the power supply buildings should be stabilized withan air-conditioner.
The circuit breaker was accidentally opened forthe power supplies of the main quadrupole and sextupole magnets. The beam orbit then moved toward
the SX electrostatic septum (ESS) unintentionally. This
resulted in fatal damage to the ESS ribbons. We thenhad to reschedule the user operation to replace the ESS
with a spare.
FX-mode operation
In March, just after the ESS ribbon failure, elevendays were assigned for the FX operation including thebeam tuning. After the vacuum chamber baking withbeam, the beam power of 510 kW was achieved for the

Fig. 1. M
 R beam power in JFY2020. The beam power of SX
and study is shown in red and that of FX and study isshown in blue (out of scale).

J-PARC Annual Report 2020

Accelerators

13
FX operation, the same as the operation in JFY2019. The
beam availability for the neutrino facility was 69.8% in
JFY2020. A trouble occurred on the power supply of theinjection septum 2 magnet. The photocoupler IC in thecontrol board was found to be damaged. Because otherparts of the power supply may not be reliable either,maintenance is again required for the stable operation.
Toward the 1.3-MW operation
The beam power of 500 kW was achieved withthe cycle time of 2.48 s and accelerated protons of
14
2.6×10 per pulse. The original beam power target
14
is 750 kW with the cycle time of 1.32 s and 2.1×10
protons per pulse (ppp). Even further beam power has
been demanded from the neutrino user community forthe discovery of CP violation and precise measurementof the mixing parameters in the lepton sector. A newtarget of 1.3 MW is planned with the cycle time of 1.16 s
14
and 3.3×10 ppp (Table 1).
Table 1. Beam Power Upgrade Concept.
Beam
Power

Cycle
Time

Number ofaccelerated protons

Present

500 kW

2.48 s

2.6×10 ppp

Original
Design750 kW

1.32 s2.1×10 ppp

New Plan

1.3 MW

1.16 s

3.3×10 ppp

14

14

14

The new magnet power supplies have been
constructed. All six power supplies for the bending
magnets were completed by the end of JFY2020. The
test operation of the 1.3 s cycle was successfully done.
The production and installation of new magnet power
supplies will be completed by JFY2021, and a test operation is planned for April and May of 2022.
Two second harmonic cavities were installed atinsertion A during the summer shutdown (Fig. 3). The
power amplifier will be installed in JFY2021. The present
two second harmonic cavities will be converted to fundamental cavities. The total number of the fundamental

cavities will then become nine, the accelerating voltage
should be sufficient for the 1.32 s operation.
The injection and FX devices have been prepared
for the faster cycling. For the injection kickers, design
work is in progress for the cooling of the matching
resistor box. Injection septum magnets and the power
supplies were replaced and ready for the 1-Hz operation. For the FX kickers, a high voltage charger was
upgraded and ready for the 1-Hz operation. New FX
septum magnets are being tested. All these devices will
be installed in JFY2021 and ready for the beam operation in JFY2022.
Two of additional collimators were constructed in
JFY2020. They will be installed in JFY2021. Another collimator is planned to be constructed in JFY2021. The
collimation system in the MR injection region must be
upgraded for a capacity of 3.5 kW beam loss as compared to the present 2 kW.
Further upgrade is planned for the operation of
1.16 s. The number of RF cavities should be increased
for the faster acceleration. The RF anode power supplies
should be upgraded for the beam loading compensation of high-intensity beams. The upgrade is planned
for JFY2025. Circuits of beam position monitors will be
upgraded for high-intensity beams and more precise
measurements by JFY2024. With the parameter tuningof the main magnet power supplies for the 1.16 s operation and the beam tuning for higher intensity, we planto achieve the beam power of 1.3 MW in JFY2028.

Fig. 3. Second harmonic RF cavities installed at insertion A.

Materials and Life Science
Experimental Facility
Overview
During the COVID-19 pandemic, a state of emergency was officially announced by the Government ofJapan on April 14. J-PARC was forced to limit users visits for 47 days and imposed an unscheduled outage for
13 days in FY2020. The difficulties with the users visits
affected seriously the user program of the MLF. Because
domestic travel was limited and no user could visit the
MLF from abroad for experiments, mail-in type experiments were performed with the dedicated supportof the MLF staff. We tried to conduct as many experiments as possible in the 2020A period, however, many
experiments were carried over to the 2020B period.
Consequently, the available beam time to accept new
proposals in the 2020B period decreased. 2020B and
2021A were called simultaneously.
Personnel exchange programs, such as AONSAYoung Research Fellowship and SAKURA programwith ESS, were postponed. Also, the annual meetingof industrial application at the MLF and the NeutronMuon School were canceled. Meanwhile, Neutron
Advisory Committee, Muon Advisory Committee,
J-PARC International Advisory Committee, Quantum
Beam Science Festa, which is an annual conference
mainly for domestic users of MLF J-PARC and IMSS KEK,
were held on-line.
The proton power ramp up on the neutron target and instrument upgrades were kept in progressunder COVID-19. In fiscal year 2020, the beam operation started with beam power of 500 kW and the beam
power was raised to 600 kW on May 18. At the endof the beam operation before the summer outage,high-power operation was maintained for 36.5 hours
at 930 kW from June 25 to 27, much longer than the10.5 hours achieved in 2019. The validity of the systemdesign regarding a stable 1-MW operation was reconfirmed. A new detector module for a time-of-flight Laue

Materials and Life Science Experimental Facility

J-PARC Annual Report 202016
single-crystal diffractometer installed in BL18, SENJU,
was developed based on scintillator and wavelengthshifting fiber technology. The thickness was reduced to
60% of the original detector. Constructions of the muon
beam lines, H-line and S2 area, progressed. Automaticand remote experiment environments of neutron beamlines were implemented to realize efficient experiments
under COVID-19.
The Efforts to make the user program successfully under COVID-19 conditions will be continued bydiscussions with users and sharing know-hows withinternational facilities.

Neutron Source Section
In fiscal year 2020, the neutron source section
started the beam operation with beam power of 500 kW,
but it was forced to stop it from April 20 to May 15 dueto the coronavirus pandemic. After the beam operation
was resumed, the beam power was raised to 600 kW on
May 18 and the stable operation continued. This was
the first achievement to operate over 500 kW for longterm user program. At the end of the beam operation
before the summer outage, high-power operation wasmaintained for 36.5 hours at 930 kW from June 25 to 27,
much longer than the 10.5 hours achieved in 2019. This
made it possible to obtain significant operation data,
which normally would require long time to reach a stable value. Also, the validity of the system design withregard to the ultimate power goal was reconfirmed.
Another notable achievement was the successful
operation of the new-type target vessel, target #11, in
which the coupling-free structure between the inner
mercury and the surrounding outer water shroud
removes the structural cause of generating high thermal stress on the target. This was one of the major
milestones to achieve stable and long term operation
at 1 MW.
During the summer outage, replacement of the
proton beam window was carried out after 3 years
operation since the last replacement in 2017. Because
the used proton beam window is a highly radioactive
component irradiated within a relatively short periodof time, in a situation similar to that of the used target
vessel, it will be transported to RAM (Radio ActivatedMaterials) building in near future.
There was also an important outcome in the pitting damage mitigation technology of the target
vessel to achieve a stable 1-MW operation. Injectionof micro-bubbles of helium gas into the mercury flowin the target vessel was used to reduce the intensity ofthe pressure waves which caused pitting damages. In
addition to that, the narrow channel has been made byadding an inner wall at the forefront wall of the target
vessel to mitigate the pitting damage by a steep velocity

Fig. 1. Cutting machine (top) and structure of the target vessel (middle) and the surfaces of an inner wall specimen(bottom)

gradient of rapid mercury flow. Specimens were cut out
from the forefront wall of target vessel #11 by hole-saw
drilling machine. The bottom picture in Fig. 1 showsthat the pitting damages on both the narrow channelside and the bulk side of the inner wall specimen arevery small, even after the long run of the 600-kW operation. These results demonstrated the excellent effect ofthe present technology for pitting damage mitigation
and are promising for further power ramp-up.
Target vessel #11 was replaced with a new target
vessel but misalignment of the coolant pipe position
led again to a target replacement with another sparetarget, which caused delay in the maintenance schedule. To prevent recurrence of this failure, the fabricationand inspection procedure for the target vessel was
improved.
The beam operation for the user program started
on December 1 after three weeks delay from the

J-PARC Annual Report 2020

Materials and Life Science Experimental Facility

17
original schedule. The neutron source continued its
stable operation at 600 kW after the summer outage

period and the average operational efficiency in fiscal
year 2020 reached 91%.

Neutron Science Section
1. Renewal of Neutron Science Section
The Leader and Sub-Leaders of the Neutron
Science Section were replaced in April 2020: Dr. Kenji
Nakajima by Dr. Yukinobu Kawakita, Prof. Shinichi Itohand Dr. Yukinobu Kawakita by Prof. Tetsuya Yokoo and
Dr. Mitsutaka Nakamura, respectively.
2. Activities under the pandemic situation
In 2020, the COVID-19 pandemic situation became
worse. A state of emergency was officially announced
by the Government of Japan on April 14th, whichcaused the cancelation of the MLF beam operation from
April 20th to May 14th. After the operation of the MLF
resumed on May 15th, the accessibility was graduallyextended from in-house use and mail-in experiments
to all users access on June 19th. The experiments which
could not be performed were carried over to 2020B
term. To calm competition rate for new proposals,
2020B and 2021A were simultaneously called. Among
384 neutron general proposals, 200 were approved tobe conducted by July 2021. The beamlines available for
the Fast-Track Proposal (FTP) were timely added in thefall, so that 7 beamlines - BL08, BL11, BL16, BL17, BL18,
BL21 and BL22, are available for FTP. The long-term proposal (LTP) was not called for the 2021 round, because
all approved LTPs showed certain delay in the experimental plan and therefore a half-year elongation of theapproved term was accepted. A new category, “oneyear proposal”, was introduced to BL11 PLANET aiming
at promotion of research projects that include technology development in collaboration with the instrumentgroup.
Under the pandemic, many user experiments werecarried out by the instrument group, as shown in Fig. 1,
instead of the users, because the latter were not able
to come. For some of the beamlines popular among
foreign researchers, this rate exceeded 50% of the conducted experiments. Developments of remote accessand automation of the instruments have emerged as
an urgent issue. The government also supported ouractivities by an additional budget (PRISM) of 55 million
JY prompting collaboration among industry, government and academia.

Fig. 1. Rate of the experiments with or without user visit
among the conducted experiments.

3. Instrumentation kept up to date
The update of the new beamline instrument,
POLANO (BL23) started as a part of the user program in
2019. POLANO is a polarization inelastic spectrometer,currently operating in an unpolarized-mode only forthe user program. Unfortunately, all proposed experiments were canceled because of the COVID-19 issue.
For the future polarization experiment, spin exchange
optical pumping (SEOP) polarizer system, and several
magnets for the guide field were almost ready to startcommissioning. Vin Rose (BL06) is a neutron spin echo(NSE) spectrometer consisting of two different types of
NSE instruments, namely, a modulated intensity by zeroeffort (MIEZE) type instrument and a neutron resonancespin echo (NRSE) type instrument. The user program
was served by MIEZE with a 4-Kelvin GM cryostat andan electromagnet generating a field up to 0.6 Tesla.
4. Award
BL08 group (S. Torii, K. Oikawa, M. Hagihala, C.
Kwanghee, T. Kamiyama) received the Technical Awardby the 20th Annual Meeting of the Japanese Society for
Neutron Science for the achievement of “Developmentof the World’s Highest Resolution TOF Type Powder
Neutron Diffractometer, SuperHRPD.”

Materials and Life Science Experimental Facility

J-PARC Annual Report 2020

18

Neutron Device
The Neutron Instrumentation Section of the MLF
Division has been engaged in the upgrade of the SENJU
diffractometer. SENJU is a time-of-flight Laue singlecrystal diffractometer installed in BL18 in the MLF. 37
detector modules have been in service since 2012 [1]. The
recent upgrade includes additional new detector modules, which are placed in obliquely downward scattering
direction to increase the total angle coverage. To fit in
the tight space constraint, the thicknesses of the detector modules have been reduced to 60% of the original
detector while maintaining the similar neutron-sensitive
area and pixel size. The intensive development of thedetector components led to the successful improvementof the count uniformities and efficiencies of the newdetector.
Figure 1 shows a photograph of the prototype
detector module. The detector is made on the basis of
scintillator and wavelength-shifting fiber technology.
Each detector module maintains a neutron-sensitive
area of 256 × 256 mm with a pixel size of 4 × 4 mm. The
6
Li:ZnS scintillator screens purchased from SINTACOR
with thicknesses of 0.25 and 0.45 mm are implemented
for upstream and downstream of the WLS fibers, respectively. New discriminator electronics cards that havea 1.8-fold wider frequency bandwidth (~500 MHz)
compared to the original ones [2] were developedand implemented to the detector as well. These new
discriminator cards help the detector pick up weakersignals with 100 V less operational PMT voltage. Figure 2
shows the comparison of the count histograms when thedetector is irradiated with neutrons uniformly over thedetector face [3]. With the new cards the count uniformity improved to 4.3% from 6.0% of the original ones.
As of the detection efficiency, the detector exceeded
the original detector for neutron-wavelengths from 1 to
12 Å, which is 50-55% for the 2-Å neutron. The detector
60–5exhibited a Co gamma-ray sensitivity of ~1 x 10 andbackground rate ~0.1 cps/hr, which are acceptable foruse in the beam line. The specifications of the developed
detector are shown in Table 1.
In summary, the new two-dimensional scintillation
detector was developed for the new detector bank of
SENJU. The produced four detector modules exhibited
similar detector performances but had improved countuniformities and detection efficiencies compared tothose in the original detector. These detectors have been
implemented at obliquely downward scattering bank in
the SENJU and have been in service since this year.

Fig. 1. A photograph of a prototype detector specifically designed for obliquely downward scattering bank of the
SENJU.

Fig. 2. Count histogram distribution for the x-projection data(a) with original discriminator cards, and (b) with new
discriminator cards [3].
Table 1. Detector specifications

References[1] T. Kawasaki, et al., Nucl. Instrum. & Meth. A 735 (2014) 444.
[2] T. Nakamura, et al., JPS Conf. Proc. 33 (2021) 011097.
[3] T. Nakamura, et al., 2020 IEEE NSS/MIC Conference Records,
pp. 1-3, N20-215.

J-PARC Annual Report 2020

Materials and Life Science Experimental Facility

19

Muon Section
1. Development of real-time temperature monitoring system for the muon target
Real-time monitoring of the target temperature is
extremely important to prevent severe accidents in therotating target system. While thermocouples have been
installed on the cooling jacket to measure the temperature rise due to thermal radiation from the rotatingtarget, the slow response of thermocouples (typicallyin minutes) makes it difficult to detect a sudden temperature rise caused by some serious trouble, such as
target rotation stoppage. For the real-time temperaturedetection, we have been developing a monitoring system based on the infrared (IR) camera.
Figure 1a shows the temperature distribution of therotating target during the 1-MW operation observedby the IR camera. The high-temperature part (shownin yellow) can be observed flowing from the center of
the target to the right (the direction of rotation). The
measured temperature rise of the rotating target at thestart of the beam operation is shown in Fig. 1b, where it
takes about one hour using thermocouples to reach theactual temperature inferred from the IR camera.
The real-time sensitivity of the IR camera is also
demonstrated by the temperature fluctuations associated with the fluctuations of the irradiated beam shownin Fig. 1b. The analysis regarding the relationshipa)Temperture (a.u.)b)

between the temperature change and thermal conductivity upon proton beam irradiation is in progress forthe 1-MW operation.
2. Construction of the H-Line
The H-line is a new beamline under construction since FY2012 in Experimental Hall #1 of the MLF
building. Its layout drawing is shown in Fig. 2. It is a general-purpose beamline that can deliver both decay andsurface muons and has branches to two experimental
areas named H1 and H2. The designed surface muon
8flux reaches 10 muons/s with a proton beam powerof 1 MW owing to a large acceptance (108 mSr) capture solenoid and other beamline magnets with large
apertures.
In FY2020, the construction of the main (upstream)part of the H line and the first branch (to the H1 Area) progressed to secure the minimal components required todeliver muons to the H1 Area for beam commissioning.
All vacuum devices were connected (see Fig. 2), electrical cabling and cooling water piping for two bending
magnets (HB1 and HB2) were conducted, and a safety
interlock system was implemented to be incorporated
into the whole MLF system. Although the capture solenoid (HS1), transportation solenoids (HS2 and HS3),
focusing quadrupole triplets, and a DC-separator are
not ready, the surface muon flux is expected to be5
6×10 muons/s without these components. In the next
summer shutdown, we plan to conduct the remaining
works such as electrical cabling and cooling water piping of all magnets and installation of a DC separator
8
and beam slits to achieve the design intensity of 10
muons/s.

IR camera

Thermocouple

18:00

18:30

19:00

19:30

Fig. 1. a) An infrared (IR) camera image of the rotating target
during 1-MW-beam operation. b) Temperature rise of therotating target upon resump-tion of the beam operation.
The temporary beam halt at around 18:50 is clearly identified by the target temperature monitored by the IR camera.

Fig. 2. a) A layout drawing of the H-line, and b) a snapshot
stshowing vacuum devices for the beamline to the 1
branch, which were connected during the summer
shutdown in FY2020.

Materials and Life Science Experimental Facility

J-PARC Annual Report 2020

20
Progress was also made in preparing the second
branch of the H-line (to the H2 Area). Since the muon
g-2/EDM experiment proposed for the H2 Area requires
a 50-meter LINAC to accelerate muons to 212 MeV, theconstruction of an extension building is planned on theeast side of the MLF where the parking lot is located.
In FY2020, the detailed design of the extension building was completed, and geotechnical investigation andburied cultural property research were conducted on
the construction site.
3. Laser system for Ultra-slow muons
Ultra-slow muons can be generated by resonant
optical ionization of thermal muonium from hot-W foil
target. Light pulses of 122.09 nm (Lyman-α) and 355 nm
are required for the 1s to 2p state excitation and 2p toionization, respectively. The high power pulsed coherent Lyman-α light source is one of the key elements forthe efficient generation of ultra-slow muons.
In FY2020, more than 10 µJ Lyman-α pulses havebeen stably generated from 212.556 nm and 820 nm
light pulses using the two-photon-resonant four-wavemixing method attained by nonlinear wavelength
conversions of a 100 mJ 1062.78 nm pulse deliveredfrom Nd:YGAG (1 at.% Nd doped Y3Ga2Al3O15) ceramic
laser amplifiers. Although we are targeting 1J-level1062.78 nm pulses to achieve the required Lyman-α
output power, the problem of Ga inhomogeneity in
Nd:YGAG has prevented for years the realization of thelarge-aperture laser medium (>10 mm in diameter) for
the amplifier required for this purpose.
To overcome this problem, we have been developing Nd:YSAG ceramic (Ga substituted with Sc), anda newly fabricated middle-size (ø9 mm, 112 mm long)
Nd:YSAG ceramic was delivered for testing the amplification gain and wave-front distortion. While theamplification gain was satisfactory, distortion of thetransmitted wavefront was exposed, which resulted
in the reduction of the wavelength conversion efficiency in the subsequent stages due to the collapsed
beam shape. In order to compensate for the distortion
occurring inside the Nd:YSAG ceramic, we introduced
an active 40-segment deformable mirror combinedwith the Shack-Hartmann wave-front sensor that wasplaced before and after the amplifier, respectively. Thea)b)Fig. 3. The wavefront distortion in Nd:YSAG ceramic for final
amplifier before (a) and after (b) after the compensation
by a deformable mirror system.

measured wavefront distortion is shown in Fig. 3, where
the distortion is removed after the compensation. The
method obtained by these studies will be applied to apractical laser system to implement the enhancementof Lyman-α optical intensity.
4. Construction of the S2 Area
The S2 Area is under construction for the precise measurement of the muonium 1s-2s transition energy by theresonant laser ionization (S1-type proposal by Okayama
U. group, supported by Kakenhi). To allow for the laser
experiment and ensure safety, the entire area is shadedby walls and removable roofs. The muon beam interlock
system is almost the same as that for the S1 Area. A laser
hut has been installed next to the S2 Area for immediate
access. The hut is made of a marine container, so that it
can be easily moved by crane. The construction of the S2Area has been nearly completed in the summer shutdownof FY2020. The rest of the work will be completed after
the approval from the Nuclear Regulatory Commission todeliver the first beam in the early FY2021.

Fig. 4. A snapshot of the S2 Area (with roofs tempo-rally removed) and laser hut viewed from the down-stream of
the S-line.

R. Kadono1,2, K. Shimomura1,2, A. Koda1,2, P. Strasser1,2, T. Yamazaki1,2, S. Kanda1,2, S. Takeshita1,2, Y. Ikedo1,2,
Y. Kobayashi1,2, J. Nakamura1,2, T. Yuasa1,2, N. Kawamura1,2, Y. Oishi1,2, Y. Nagatani1,2, S. Mato-ba1,2, S. Nishimura1,2,
S. K. Dey1,2, W. Higemoto2,3, and T. U. Ito2,32
1Institute of Materials Structure Science, KEK; Muon Science Section, Materials and Life Science Division, J-PARC Center;3
Advanced Science Research Center, JAEA

Materials and Life Science Experimental Facility

J-PARC Annual Report 202021

Technology Development Section
0.50

2D detector
512×512 pixels@ 24.3 m

0.40

Edge position(strain)

0.30
0.20

0.30

Measured_tooth
Fitted_toothMeasured_core
Fitted_core

0.10

0.20

0.00
3.9

0.10
0.00

Applied to induction hardened gears at the MLF
Induction hardening, as an important heat
treatment method, aiming for a hard martensitic
microstructure in gear’s teeth region, leads to significant improvement in the mechanical properties of thecomponents. Residual stress and microstructure play
an important role in forming the desired propertiesof gears. In the present study, we applied the Braggedge broadening analysis to gear products. Using
this method, the residual strain and microstructural
distribution of two types of induction-hardened gear
products manufactured by Neturen Co., Ltd. were analyzed [1].
Figure 1 shows the Bragg-edge imaging experimental setup at BL22 RADEN [2]. Figure 2. shows acharacteristic Bragg-edge transmission spectrum of
the measured sample. The Bragg-edge position, d 110,
and the Bragg-edge broadening, w110, were obtained
via single-edge fitting. Bragg-edge broadening was
confirmed at a position in the gear’s teeth region. This
indicated the formation of a martensitic microstructurein the hardened zone due to induction heating.

0.50

0.40

Transmission

Neutron Bragg – edge transmission imaging
The time-of-flight neutron Bragg-edge transmission imaging, one of the advanced energy-resolved
imaging techniques, can be used to directly visualize
the two-dimensional distribution of crystallographic
information and residual strain of bulk materials. We
have developed this technique and applied it to various engineering materials at the MLF.

1.5

4.0

4.1

4.2

4.3

220

211

2.0

2.5 3.0 3.5 4.0
Wavelength ( )

200

110

BCC

4.5

5.0

Fig. 2. An example of the Bragg-edge spectrum measured
and BCC 110 edge fitting for edges from the core
and the tooth region of a gear sample.

The obtained 2D maps for the elastic residual strain,
ε110, shown in Fig. 3, represent the first-ever maps madeusing the Bragg-edge imaging method. Compressive
residual strains were generated in the martensite
hardened zone of both gears, while the strain wasalmost zero in the core region. A steep compressive
strain was introduced into the fine – grained martensite at the tooth surface of the finished product by thesuper rapid induction – heating process. The results
were in accordance with those obtained using the XRD
measurement.
(a)

(b)
ε110

Fig. 3. 2D maps for residual strain of 110 lattice plane obtained via Bragg-edge imaging: (a) a precursor and(b) a finished product.

Incident beam

B4C shield

Side view
28 mm

Sample-

28 mm
104 mm

We have demonstrated that we can reveal microstructural features and residual strains in gears using
the non-destructive Bragg-edge imaging. This technique would be applicable to other induction-hardened
products or heat-treated machine parts.
References[1] Y.H. Su et al., Sci. Rep., 11 4155 (2021).
[2] T.Shinohara et al., Rev. Sci. Instrum. 91 043302 (2020).

Overall view

Close-up viewFig. 1. Experimental setup at RADEN.

Particle and Nuclear Physics

Neutrino Experiment
After a one-year no-beam period, a T2K data acquisition was started in fiscal year 2020 in the neutrino
mode on March 8, 2021. After vacuum chamber scrubbing and beam tuning, a stable operation of 510 kW
beam power was successfully achieved. The accelerator operation continued until the end of April, with aninterruption for hadron beam operation.
During this period, the T2K experiment was performed without the off-axis detector ND280 operation
owing to COVID-19 travel restrictions. Three neardetectors, Wagasci, BabyMIND, and on-axis INGRID,
were operated by on-site experts and monitored
remotely by collaborators overseas. The far-detector
SuperKamiokande operated successfully for the firsttime with a beam after gadolinium was dissolved anddemonstrated improved neutron detection capability.
As of March 19th, since the beginning of the experi20
ment, T2K accumulated 20.4 × 10 POT in the neutrino
20
mode, in addition to the 16.5 × 10 POT accumulated in
the anti-neutrino mode.
In April 2020, T2K published new analysis results
regarding CP violation in Nature magazine. This
imposed the world-first 3σ restriction on the CP phase,as shown in Fig. 1. This article was selected for the “10remarkable discoveries from 2020.”
A T2K extension, T2K-II, was proposed to further
investigate the CP violation and perform a precise measurement of mixing parameters. It has been officiallyapproved after recommendations from the J-PARC
PAC. To improve the performance of on-site neutrino

Particle and Nuclear Physics

J-PARC Annual Report 202024

Fig. 1. Top: Two-dimensional confidence intervals at 68.3%
2
confidence level for δCP vs. sin θ13 in preferred normal
mass ordering. Bottom: Two-dimensional confidence
intervals at 68.3% and 99.7% confidence levels for δCP2
vs. sin θ23 from T2K + reactors fit in normal mass ordering.

detector ND280 and to achieve a beam power beyond
1 MW, extensive efforts have been expended. The
pre-assembling of two million scintillator cubes withsupporting fibers was completed in one of the mostimportant subdetectors of the ND upgrade program,i.e., the Super Fine Grain Detector (SuperFGD), as shownin the IPNS cover page. Also presented a schematic layout of cubes and wave-length-shifter fibers crossing in
the x-,y-, and z-directions for a three-dimensional (3D)
readout.
The E71 Ninja experiment is a precision study ofneutrino–nucleus interactions with hybrid emulsion
detectors. Their unique analysis procedure was prothvided in a press release on October 20 . The excellent
spatial resolution of the emulsion combined with anovel timestamp mechanism enabled the reconstruction of neutrino interactions with unprecedented
position precision. In March 2021, a pilot experimentwith a heavy-water target was conducted.
2
The JSNS experiment searches for sterile neutri—nos with short baseline neutrino oscillations from Vμ—
to Ve at the MLF. The experiment was commenced fromJanuary 2021, and data was acquired smoothly. Details
2regarding the JSNS experiment are reported in the
Research Highlights.

Hadron Experimental Facility
The Hadron Experimental Facility of J-PARC wasdeveloped for fixed-target particle and nuclear physics experiments. In FY2020, a primary proton beam
can be used at a new beamline (B-line) in addition to
the secondary hadron beams produced at the production target (A-line) based on a slowly extracted 30-GeV
proton beam from the Main Ring accelerator. A small
amount of the beam to the A-line was separated using a
Lambertson magnet and delivered to the B-line experimental area.
Commissioning for the B-line was commenced anda new production target that can receive a 95 kW prird
mary beam at the A-line was set on May 23 . The firstthbeam to the B-line was extracted on May 24 (Fig. 2).
thBeams were delivered to users until June 26 .
th
The second beam operation from December 14
was interrupted several times owing to several problems but was completed on April 7, 2021. During thistime, 60 kW of beam power to the A-line was achieved.
Several beam tunings of the B-line were performed, andthe beam qualities such as beam stability and intensity
fluctuation during extraction were improved.

Fig. 2. The first shot to B-line measured with Ion Chamber(IC) at a beam-dump. Horizontal is time in millisecond
while vertical is IC counts.

J-PARC Annual Report 2020

Particle and Nuclear Physics

25

Strangeness/Hadron Physics Experiments
In the E40 experiment at the K1.8 beamline, which
is a Σ hyperon-proton (p) scattering experiment, data+acquisition of the Σ p scattering data was completed
from May to June 2020. From the middle of December
after the detector rearrangement at the K1.8 beamline, the E03 experiment was performed to observeΞ-atomic X-rays for the first time and to obtain information regarding the Ξ-nucleus potential from the level
shift and width.
At the K1.8BR beamline, pilot data were collected3
in June for the hyper-triton ( Λ H) lifetime measurement
43(E73), using a liquid He target instead of He to verify
the methodology. The production and weak decay of4
Λ H were identified.
Detector commissioning was performed and Run-0
data were acquired by the E16 experiment such thatthe primary proton beam at the B-line can be used. The
aim of this experiment was to investigate the invariantmass spectrum of di-electron pairs in the φ-meson
region in proton– nucleus collisions.
Several results from the experiments were published in FY2020. The E15 experiment observed–
K pp-bound system and its binding energy and decay
width were reported to be BK = 42±3(stat.) +3–4(syst.)+19
MeV and ΓK = 100±7(stat.) –9(syst.) MeV, respectively.
–
11
In the K + B system, an event excess was observedin the deeply bound region of the missing-mass spectrum measured in E05. The corresponding binding–
energy was higher than that of the K pp system above.
In the emulsion experiment, E07, several events of– 14
Ξ-hypernuclei (Ξ + N system) were observed.

Kaon Decay Experiment
The KOTO experiment was designed to investigate
the decay of a long-lived neutral kaon into a neutral
π meson (π0) and a pair of neutrinos. It breaks the CP
symmetry directly, and its branching fraction is theo−11
retically well predicted in the SM as (3.0 ± 0.3) × 10 .
The detection of this decay is challenging because only0
two photons from π are observable, and the decay
mode has not been observed. By examining this ultrarare decay, a new source of CP symmetry breaking thatcan explain the matter-antimatter asymmetry in theuniverse may be revealed.
In FY2020, the results from data accumulated in
2016–2018 from the KOTO experiment were pub−10
lished. With a single event sensitivity of 7.2 × 10 ,three events satisfied all the selection criteria, whereas
the expected number of backgrounds was evaluatedto be 1.22, which is statistically consistent with theobservation. KOTO set the upper limit for the branching0−9
fraction of KL→π νν in this dataset to 4.9 × 10 at the
90% confidence level. To reduce the newly found background due to the contamination of charged kaons in
the neutral beam, a new detector, named the Upstream
Charged Veto (UCV), was installed at the entrance of the
KOTO detector in December. The activities performed
are described comprehensively in Research Highlightsof this report. Data acquisition using the UCV is being
continued in the KOTO experiment to achieve better
sensitivity.

Muon Experiments
COMET aims to identify muon-to-electron con−14
version with a sensitivity higher than 10 . Intensive
research and development were conducted in 2020. A
cylindrical drift chamber was successfully tested using
cosmic-ray muons with a full setup of readout electronics
and a remote control system. The construction of a straw
tube tracker and the mass production of lutetium yttrium
orthosilicate (LYSO) crystals for the electron calorimeteris currently in progress. The construction of a capturesolenoid (CS), which is used to acquire and transport
pions/muons produced by the COMET primary proton
target, as well as the preparation of a cryogenic system,
is in progress. The assembly of superconducting coils
was completed in 2020. A cryostat to contain and cool
coil assemblies down to the liquid helium temperature
will be constructed in 2021, followed by coil installation

Particle and Nuclear Physics

J-PARC Annual Report 202026
into the cryostat in 2022.
The E34 collaboration is preparing for precision
measurements of the anomalous magnet moment(g-2) and electric dipole moment (EDM) of muons. The
collaboration continued the development of the roomtemperature muon source, linear accelerators, beam
injection beamline, storage magnet, and positrondetector. Preparation was performed for facility construction, such as grounding surveys, geotechnicalsurveys, and surveys of buried cultural properties at theconstruction site. Important achievements in the development of a muon source and a frontend ASIC for thesilicon strip detector, which will be described in a later
section (Fig. 3), have been published as technical papers.

Theory group
The mission of the theory group at the J-PARC branch
is to investigate the theoretical aspects of particle andnuclear physics in collaboration with the experimentalgroups. The group consists of four IPNS staff members
and five visiting researchers.
Owing to the COVID-19 pandemic, the activitiesof the theory group were mainly conducted online.

Seminar series on J-PARC heavy-ion project, and twointernal online workshops on “Physics of heavy-quarkand exotic hadrons 2021” and “Beta decay, r-process,and related weak-interaction processes” were organizedby the group members. More than ten research papers
were published in 2020.

Technical Support Groups
The electronic system group constructs electronicsystems through a framework known as “Open-It.”
Regarding the J-PARC experiments, the mass productionof a 128 channel silicon strip readout application-specificintegrated circuit was completed for the g-2/ EDM experiment (Fig. 3).
The predominant activities of the mechanical engineering group are collaborative investigations during
various experiments, including T2K and COMET. The conceptual design for the COMET radiation shield has been
completed.
Fig. 3. Photograph of front-end ASICs for silicon-strip sensors
in the g-2/ EDM experiment.

J-PARC Annual Report 2020

Particle and Nuclear Physics

27— Research Highlight —2
The JSNS experiment gets started!!
J-PARC Sterile Neutrino Search at J-PARC Spallation
2
Neutron Source (JSNS ) [1, 2] started data taking fromJanuary 2021. This article introduces the motivation,2
history and status of the JSNS .
2
JSNS aims to search for sterile neutrinos, which are
new particles that exist beyond the standard model of
elementary particle physics. They had no weak interactions and felt only gravity. To explain the sterile neutrino,
the simplest model is to introduce right-handed neutrinos in each generation. They were initially indicated by
the Liquid Scintillator Neutrino Detector (LSND) experiment [3] in the 1990s, and several experiments havesince been conducted to confirm or refute the existence of sterile neutrinos. Some claim positive results,
while others show negative results. Please refer to thecitation [4] for the experiments in the review. In this2
situation, the JSNS experiment started data taking toconfirm or refute their existence as a direct and ultimate
test of the LSND.

Fig. 1. Setup of the JSNS2 experiment.
2

Figure 1 shows the setup of the JSNS . We locate andmove the detector every year twice, thus, seventeen
tons fiducial volume of a (Gd-loaded liquid scintillator
detector (50 tons in total) is placed on the third floorof the Materials and Life Science Experimental Facility(MLF) building.The mercury target of MLF produces a
number of neutrons in the collisions of the three GeV
short pulsed protons accelerated by the rapid-cycle
synchrotron (RCS) of J-PARC to study the material andlife sciences; however, many neutrinos are simultane2
ously produced. JSNS uses the anti-muon-neutrinos
produced by the decay-at-rest of the muons. Because
the parent particles of neutrinos have zero momentum

during production, neutrinos produced by the decay-atrest have a well-known energy. The short pulsed three
GeV proton beam can easily separate the background.

Fig. 2. The principle of the anti-neutrino production at thetarget and detection at the scintillator detector.

Figure 2 shows the experimental principle, particularly for neutrino production and detection. At the
mercury target, the anti-muon-neutrinos are producedin collisions with three GeV protons through the muon
decay-at-rest. After the production of anti-muon-neutrinos, neutrino oscillation between anti-muon-neutrinos
and anti-electron-neutrinos occurred at 24 m throughsterile neutrinos. The liquid scintillator detector isextremely effective in detecting anti-electron-neutrinos because they create inverse-beta-decay (IBD)—+
signals ( νe + p → e + n ). The IBD signal produces two+sequential signals from e and neutron-Gd captured
signals inside the liquid scintillator; therefore, the accidental background is significantly reduced by requiring
the two signals for analysis.
2
JSNS experiment was proposed in 2013 for the
J-PARC. The final approval to start the experimentfrom the J-PARC was granted in November 2018. The
construction of the detector began in 2017 and wascompleted in February 2020. Figure 3 shows the pictures of the detector. 10-inch photomultiplier tubes(PMTs), acrylic tank, and veto layer were used toobserve the particles coming from outside the detector.
The Gd-loaded liquid scintillator (Gd-LS) is filled inside
the acrylic tank, while the Gd unloaded liquid scintillator (LS) is filled between the acrylic and stainless tanks.
The IBD reaction is created in Gd-LS, as explained. The
optical separator made of black boards that separates

Particle and Nuclear Physics

J-PARC Annual Report 202028
the inner volume that detects IBDs and the veto region,
which identifies the charged particles coming fromoutside, is as shown in Fig. 3. Approximately 20,000 L
of Gd-LS was donated by the Daya-Bay experiment [5],and more than 80% of PMTs were donated by RENO and
Double-Chooz experiments [6, 7]. Many electronics,
such as flash ADC or front-end electronics (amplification circuit), were also donated by Double-Chooz. We
express warm thanks to these experiments.

effective search can be conducted for sterile neutrinos
using timing information. With a beam power of one
MW for three years, it will be concluded that most of theregion can be indicated by LSND.

Fig. 4. Data around the proton beam timing. The activities(most of them are neutrons created by beam) are seenin the beam timing, while the IBD sterile neutrino searchregion (the orange rectangle) is dominated by cosmic
ray induced background, which will be removed by theveto information and IBD selection criteria.

Fig. 3. (top-left): Overall detector structure inside the detector including acrylic tank. (right): 96 10-inch PMTs to
see the scintillation light from the IBD. (bottom-left):the detector view from the outside.

The commissioning run was held in June 2020, andthe first long physics run started from January 2021.
During the first physics run, the beam power of the MLF
was 600 kW until April 5, and approximately 700 kW
after April 5. The beam power approaches the design
value of 1.0 MW.
Figure 4 shows the activities around the beamtiming. Several neutrons induced by the beam areobserved in the beam timing; however, this backgroundcan be reduced using the timing of the production timeof the anti-muon-neutrinos owing to the long lifetimeof the muons decay-at-rest (2.2 ms). This indicates that

Recently, we proposed the second phase of the2experiment, JSNS -II [8]. This experiment uses 35 tonsof Gd-LS as a neutrino target with a baseline of 48 m;
2
therefore, the low Δm region of neutrino oscillation
parameters, which is a stronger indication region by the2
global fit [4], and the weak points of the current JSNS
can be searched. We conclude the LSND anomaly in thenear future.
References[1] M. Harada et al., arXiv:1310.1437 (2013).
[2] S. Ajimura et al., arXiv:1705.08629 (2017).
[3] A. Aguilar et al., Phys Rev D64, 112007 (2001).
[4] M. Dentler et al., JHEP 08, 010 (2018).
[5] M. Yeh et al., Nucl. Inst. And Meth. A584, 238 (2008).
[6] J.K. Ahn et al., Phys.Rev.Lett. 108, 191802 (2012).
[7] Y. Abe et al., Phys. Rev. Lett. 108, 131801 (2012).
[8] S. Ajimura et al., arXiv:2012.10807 [hep-ex].

J-PARC Annual Report 2020

Particle and Nuclear Physics

29— Research Highlight —First determination of the binding energyof the Ξ hyperon in the Ξ hypernucleus
Elucidation of the nuclear force (strong interaction) that acts on nucleons (Ns) and forms nuclei is oneof major topics in fundamental physics. One trial is toextend the nucleons consisting of up (u) and down (d)+quarks to the octet baryons, including Λ(uds), Σ (uus),00Σ (uds), Σ (dds), Ξ (uss), and Ξ (dss) hyperons, by adding strange (s) quarks and to understand the interaction
between octet baryons in a unified manner. Because of
the difficulty of hyperon scattering experiments, theinteraction of hyperons is obtained mainly from dataon hypernuclei made of both hyperons and nucleons.
In contrast to a relatively large amount of informationon the strangeness of -1 (S = -1) Λ hypernuclei, dataon the S = -2 system remain scarce. Double Λ hypernuclei have presented a good method for studying ΛΛ6interaction, and the obtained binding energy of ΛΛHe
has revealed that the ΛΛ interaction is weakly attractive[1]. Recently, the Ξ p interaction was studied by ALICE
experiment [2], in which attractive interaction was suggested based on a two-body correlation.
In line with Λ hypernuclei, the study of Ξ hypernuclei
can provide meaningful information on ΞN interactions.
12+
In the missing-mass spectra of the C(K , K ) reaction,
no peak structure has been observed because of theinsufficient energy resolution at KEK [3] and Brookhaven
National Laboratory (BNL) [4]. However, the potential
depth of 14 MeV has been deduced by assuming a
Woods–Saxon type potential [4]. For the event named“KISO” identified in the emulsion experiment of KEK
E373, its formation and decay were uniquely identified
10
514
as Ξ + N → Λ Be + ΛHe [5]. Binding energy of Ξ (BΞ-)
of the formed state was obtained as 3.87 ± 0.21 MeV or
10
1.03 ± 0.18 MeV depending on whether Λ Be was in the
ground or excited state. In either case, the obtained BΞ14of the Ξ + N system is deeper than that of the atomic
3D orbit of 0.17 MeV, and the observed system is a Ξhypernucleus in which the Ξ hyperon is bound mainly
by strong interaction. It turns out that the Ξ-nucleus
potential and underlying ΞN interaction are attractive.
To determine BΞ- uniquely and obtain the ΞN interaction quantitatively, more events must be observed.
J-PARC E07 is an emulsion-counter hybrid experiment that aims to identify and observe approximately
10 times the number of events on S = -2 hypernuclei as

those in KEK E373 using a high-intensity and high-purity
K beam at the K1.8 beamline of the J-PARC Hadron
Experimental Facility. In 2016 and 2017, 118 emulsion
modules were exposed to Ξ hyperons produced by the+(K , K ) reaction on a diamond target located upstreamof the emulsion module. Through the measured position and direction information of Ξ identified with thespectrometer system, the tracks of Ξ were automatically traced to the stopping point in the emulsion, andS = -2 hypernuclei were searched for using microscope
systems.
Figure 1 depicts a remarkable event of thetwin-Λ hypernuclear topology found in [6]. This event,
named “IBUKI,” was also uniquely identified as
10514
Ξ + N → Λ Be + ΛHe, where a Ξ hyperon was cap14
tured by N to form a bound system and decayed
10
5
into Λ Be and ΛHe through the Ξ p → ΛΛ conversion process. The BΞ- was uniquely determined to be
1.27 ± 0.21 MeV because no possibility existed of theexcited daughter Λ hypernuclei. The obtained 1.27 MeV
is deeper than BΞ- of the atomic 3D orbit. In the caseof Coulomb force only, the BΞ- of the atomic 2P orbit
is calculated to be 0.39 MeV. The difference from themeasured value is due to an additional force, namely,
an attractive strong interaction between a Ξ and a

Fig. 1. Superimposed image and its schematic of the IBUKI
14
event. A Ξ was captured by N and decayed into a10510ΛBe (#1) and a ΛHe (#2) at point A. The ΛBe decayed
into several nuclei (#3–6) and several neutrons (there
were no recorded tracks because of no charge of neu54tron) at point B. The ΛHe decayed into a He (#7), π (#8),
and proton (#9) at point C.

Particle and Nuclear Physics

J-PARC Annual Report 2020

30
nucleus. This is the first precise determination of BΞ ofthe Ξ hypernucleus, which provides us the strength ofthe Ξ-nucleus potential and the underlying ΞN interaction. If the Ξ p → ΛΛ conversion is strong, the systemdecays before the Ξ reaches the nucleus and forms aΞ hypernucleus. The present result indicates that theconversion is weak.
Most recently, a more deeply bound Ξ hypernuclear
state was observed [7]. The event, named “IRRAWADDY,”5514
4
was identified as Ξ + N→ ΛHe + ΛHe + He + n withBΞ- = 6.27 ± 0.27 MeV. Figure 2 shows the BΞ- values
14of the Ξ + N system obtained from the emulsion
events. For the “KINKA” event observed in KEK E373, theBΞ- value was recently determined to be 8.00 ± 0.77 or
4.96 ± 0.77 MeV by reanalysis. With these events, the- 14level structure of the Ξ + N system has become clear.
A probable interpretation is that IBUKI and KISO (1.03
MeV) are states in which the Ξ is in nuclear 1p orbit,
whereas IRRAWADDY and KINKA are states in which theΞ is in nuclear 1s orbit.
Hyperons may stably exist in high-density matter such as the core of neutron stars, which are often
described as giant nuclei. Which hyperons appear andat which density this happens depend in the interaction between the various baryons. The present resultson ΞN and ΞN → ΛΛ interactions give us new insight
into the origin of nuclei, namely, matter in the universe,
as well as the structures of neutron stars.
Analysis of E07 emulsion is in progress. With the
newly developed overall scanning method, which does
not require counter information, 10 times the numberof events as those under the present hybrid scanning
method are expected to be detected. Then, S = -2
baryon interaction will become more apparent.

Fig. 2. Binding energies of Ξ- in the Ξ-+14N system derived
from the emulsion experiments at KEK E373 and JPARC E07 [7]. For the atomic 3D state, a Ξ is located far
from the nuclear surface where the strong interaction
does not work with the orbital angular momentum l =2. However, a Ξ is located near the nuclear surface orinside the nucleus where strong interaction works withl = 1 or 0 for nuclear 1p or 1s states, respectively.

References[1] H. Takahashi et al., Phys. Rev. Lett. 87, 212502 (2001); J.K. Ahn
et al., Phys. Rev. C 88, 014003 (2013).
[2] S. Acharya et al., Phys Rev. Lett. 123, 112002 (2019); ALICE
Collaboration, Nature 588, 232 (2020).
[3] T. Fukuda et al., Phys. Rev. C 58, 1306 (1998).
[4] P. Khaustov et al., Phys. Rev. C 61, 054603 (2000).
[5] K. Nakazawa et al., Prog. Theor. Exp. Phys. 2015, 033D02(2015); E. Hiyama and K. Nakazawa, Annu. Rev. Nucl. Part. Sci.
68: 131 (2018).
[6] S.H. Hayakawa et al., Phys. Rev. Lett. 128, 062051 (2021)[7] M. Yoshimoto et al., Prog. Theor. Exp. Phys. 2021, 073D02(2021)

J-PARC Annual Report 2020

Particle and Nuclear Physics

31— Research Highlight —Updated results from KOTO
The K L → π0 ν –ν decay, in which a neutral kaon (K L)
0decays into a neutral pion (π ) and a neutrino-antineuν), could potentially provide a clue to thetrino pair (ν –new physics beyond the standard model (SM). In theSM, its branching ratio has been calculated to be as low-11
as 3 × 10 , which implies that the effect of new physics
on the decay could overwhelm that of the SM. Owing
to the exceptionally small uncertainty in theoretical calculations, any observed deviation from the prediction is
directly related to the existence of new physics.
The KOTO (standing for ”K0 at Tokai”) is a dedi0ν decay atcated experiment to search for the K L → π ν –the Hadron Experimental Facility of the Japan Proton
Accelerator Research Complex. This international collaboration consists of 60 individuals from Japan, Korea,
Russia, Taiwan, and the USA. The experiment began collecting data in 2013, and has continues to do so. The
first dataset obtained in 2013 showed that the experimental method and all detector components worked
properly [1]. With the second dataset obtained in 2015,
the world’s highest sensitivity was improved by one
order of magnitude [2]. Analysis of the third dataset collected from 2016 to 2018 was completed in 2020; thepublished results are described in this article [3].

CSI

concrete and iron shieldFig. 1. Cross-sectional view of the KOTO detector.

Figure 1 shows a cross-sectional view of thedetector. The energy and timing of two photons aremeasured in the electromagnetic calorimeter (labeled
as CsI) made of 2716 undoped cesium iodide crys0
tals. The decay position and momentum of the π arereconstructed from them. Various types of veto counters surrounding the decay region hermetically confirm
that there are no other particles accompanying the two
photons.
It is an experimental challenge to operate the vetocounters with high detection efficiency. For example,0
K L → 2π decay has four photons in the final state, andis distinguished by two additional photons. Because its
branching ratio is eight orders of magnitude greater0ν, the veto counters are required tothan K L → π ν –detect a photon with 99.99% efficiency to avoid missing the two additional photons.
0
Another challenge is to reject π production asa result of neutron interaction with matter because
the K L beam includes a large number of neutrons. To

prevent the process from occurring, the decay volume
should be maintained as a highly evacuated region.
This is realized by placing most of the detectors, including the calorimeter, into a large vacuum chamber andplacing veto counters far from the signal region.
New background sources appear along withimprovement in experimental sensitivity, and theymust be clearly understood. An important backgroundsource was found during the data analysis, in which aneutron entered the calorimeter and produced two
photon-like activities. To remove the background, thinphoton sensors, i.e., multi-pixel photon counters, were
installed in front of the calorimeter in 2018 after accumulating the third dataset. With this improvement,
KOTO continuously accumulated data, which are being
analyzed to achieve higher experimental sensitivity.

Particle and Nuclear Physics

J-PARC Annual Report 2020

32

500
450

439
436.79 ±3.83

00.53 ±0.13

00P t (MeV/c)

400
350

4
1.97 ±0.35300including signal region

250
200

3
1.22 ±0.26

150

00.14 ±0.06

100
50

0
0.20

±0.09

0
0

0

Fig. 2. Reconstructed π transverse momentum (Pt) versus
0 01000
1500 2000
2500position
3000 3500(Z4000
5500 6000
π decayvertexplot 5000
indicating
the sign t x ) 4500
0 –νν
decay.
nal region for theZKvtx
L →π
(mm)

Figure 2 shows the distribution of remaining events
for the third dataset after applying all selection crite0
ria in the plane of the reconstructed π decay position(Zntx) and its transverse momentum (P t). The region
inside the polygon indicated by dashed lines is the0ν decay. The
signal region searching for the K L → π ν –block dots represent the observed events. The coloredcontour indicates the expected density distribution of
the signal events obtained by Monte Carlo simulation.
For the three events in the signal region, the singleevent sensitivity of the analyzed data was calculated as-10
7.2 × 10 . In the process of investigating their nature
to declare them as genuine signal events, the study of±the decay of the charged kaon (K ) along with the K L±
was proposed. A K can be generated during the collision of K L with dense materials at the inner surfaceof the beam line, which enter the decay volume. Even±
with a small number of K , it could become a serious±
0 ±background source through K → π e ν decay. This is0
mainly because the kinematics of the π is similar tothat of K L → π0ν –ν decay. However, it was not possible
to evaluate the number of the background correctly±
due to the uncertainty in the number of K because areliable Monte Carlo calculation related to the process
does not exist.
In 2020, a special experiment was performed to±±± 0measure the K flux. As a result, 847 K → π π decays
were successfully reconstructed. This means that the±-5ratio of the K and K L flux is (7.2 ± 0.1) × 10 . That is, the±0 ±number of K → π e ν backgrounds is expected to be
0.9. Summing up all contributions of K L decays and neu±tron interactions to this K result, the expected numberof background events is 1.22 ± 0.26. This value is statistically consistent with the number of observed events.
With the assumption of Poisson statistics, the upper0ν decay was
limit of the branching ratio of the K L → π ν –-9set as 4.9 × 10 .
To suppress the newly observed background
events, a charged particle detector, made of scintillating fibers of 0.5 mm × 0.5 mm in cross-section, wasfabricated and installed in front of the detector. Data
collection was scheduled for two months starting inMay 2021. This will provide a similar amount of data as
the third dataset. This dataset will improve the under±
standing of the K background and its rejection by a
newly installed detector.
References[1] J. K. Ahn et al., (KOTO collaboration), Prog. Theor. Exp. Phys.
2017, no. 2, 021C01 (2017).
[2] J. K. Ahn et al., (KOTO collaboration), Phys. Rev. Lett. 122,
021802 (2019).
[3] J. K. Ahn et al., (KOTO collaboration), Phys. Rev. Lett. 126,
121801 (2021).

Cryogenics Section

Overview
The Cryogenics Section supports scientific activities
in applied superconductivity and cryogenic engineering,
carried out at J-PARC. It also supplies cryogen of liquid
helium and liquid nitrogen. The support work includes
maintainance and operation of the superconducting
magnet systems for the T2K neutrino beamline andthe muon beamlines at the Materials and Life Science
Experimental Facility (MLF) and construction of the magnet systems at the Hadron Experimental Facility (HEF). It
also actively conducts R&D works for future projects at
J-PARC.

Cryogenics Section

J-PARC Annual Report 202034

Cryogen Supply and Technical Support
The Cryogenics Section provides liquid helium
cryogen for physics experiments at J-PARC. The usedhelium is recycled by the helium gas recovery facility at
the Cryogenics Section. Figure 1 summarizes the liquid
helium supply in FY2020.
Liquid nitrogen was also supplied to the users fortheir convenience. Its amount in FY2020 is summarized
in Fig. 2. Liquid nitrogen has been regularly provided
to the Radiation Safety Section for operation of a gas
chromatograph. It was also supplied to the users in the
MLF, the HEF and the Cryogenics Section.

Fig. 1. Liquid helium supply at J-PARC from April 2020 toMarch 2021.

Fig. 2. Liquid nitrogen supply at J-PARC from April 2020 toMarch 2021.

Superconducting Magnet System for T2K
The superconducting magnet system for the T2K
experiment operated during the periods shown in
Table 1. The system worked well without disturbing thebeam time. The operation time in FY2020 was only 49
days and regular maintenance works were carried out
in the summer. Figure 3 summarizes the incidents in
the refrigeration system from FY2009 on. The system
was suspended only in its early period due to problems in the hardware and control parameters. Althougha few problems with hardware parts occurred in the
recent years, the troubles had been resolved without
interrupting the operation. The system was very stable
in FY2020 as well.

Fig. 3. Summary of incidents in the Refrigerator System for
T2K.

Table 1. Operation history of the T2K superconducting magnet system.

2020
Apr.
Operation
Maintenance

May

June

Jul.

Aug.

Sep.

Oct.

Nov.

Dec.

2021
Jan.

Feb.

Mar.

2/3-3/23

J-PARC Annual Report 2020

Cryogenics Section

35

Superconducting Magnet Systems at the MLF
The Cryogenic Section contributes to the operationand maintenance of the superconducting magnet systems at the Muon Science Facility (MUSE) in the MLF.
The superconducting solenoid in the Decay Muon Line(D-line) was operated from January to June 1, 2019,
although the operation was temporally stopped from
April 20 to May 11 due to the coronavirus. Annual maintenance, such as exchange of the oil separation filter,
safety valve maintenance and so on, was performed
from July to the end of November. During the maintenance work, a small leak was found on a flexible horse of
the He high pressure line, therefore, four horses, including three horses without a leak, were replaced just incase (Fig. 4). The cryogenic operation was restarted on
November 24. It was stopped on December 24 for the

New Year holidays, and it resumed on January 6.

Fig. 4. Exchange work of the He flexible horses.

Superconducting Magnet Systems at the HEF
The COMET experiment is under construction in the
Hadron South Experimental Hall (HDS) of the Hadron
Experimental Facility (HEF). The Cryogenics Section
was involved in the construction of the cryogenic system and superconducting magnets. Production of
the superconducting solenoid magnet for the muonsource is in progress. Superconducting coils for thePion Capture Solenoid (PCS) were inserted in the support shell structure and impregnated with the radiation

resistant resin. The coil structure is shown in Fig. 6.
The magnets are designed to be cooled by a twophase flow of liquid helium, which is supplied by ahelium refrigeration system built in HDS. The current
lead box (CLB) for the PCS was fabricated and installedin the HDS in FY2020 (Fig. 1). Five High Temperature
Superconductor (HTS) current leads for 3 kA, 500 A
and 250 A are installed. They are cooled not only by
cryocoolers but also by the shield helium gas with

Fig. 5. Insert of the current lead box for the Pion Capture Solenoid.

Fig. 6. The coldmass of the Pion Capture Solenoid (CSMS
coils).

Cryogenics Section

J-PARC Annual Report 2020

36
temperature of 40K supplied from the helium refrigerator. Performance test of the CLB will be done in FY2021.
The transfer line was connected to the small cryostat for protection diodes, which is separated from thecryostat of the MTS magnet. Since the cooling port of
MTS has an aluminum cooling pipe, an aluminum pipeshould connect the diode and the magnet. Connecting

the aluminum pipe, which ensures leak-free conditions
in cryogenic temperature with thermal shocks and thermal cycles, requires a great deal of skill. We performed
the aluminum pipe welding with high reliability andhigh yield. After this welding, we also confirmed that all–103
welding points were leak free (less than 10 Pa∙m /sec)
after a thermal shock with liquid nitrogen temperature.

R&D for the Future Projects at J-PARC
The g-2/EDM project aims for the precise measurement of the anomalous magnetic moment and theelectric dipole moment of muons. This experiment was
proposed at the MUSE H-Line. A superconducting solenoid with a high field homogeneity, better than 1 ppm
locally, plays a very important role as a muon storage
ring. The numerical study of cold box on vibration conduction was carried out. Mechanical vibration causes
errors in the magnetic field. The cold box has four GM
cryocoolers to re-condensate evaporated helium gas,
and they generate vibration. The cryocoolers were supported by the stage separated from the vacuum vesselof the cold box and connected to the cold box with soft
bellows in order to avoid direct conduction of the vibration. The frequency response analysis was carried out
with FEM software to evaluate the vibration conduction performance. The simulation study shows that theresonant vibration modes were higher than 20 Hz, thatis sufficiently higher than the main vibration frequencyof the cryocooler, 1 Hz. The coil vibration, that is error
field, caused by the conducted vibration from the coldbox will be evaluated in the next fiscal year.
A muonium hyperfine structure measurement,
called MuSEUM experiment, has been proposed for thesame beam line as the g-2/EDM project. In the experiment, the energy state transition in muonium will beobserved under a static magnetic field with local homogeneity of 1 ppm. A new NMR readout board were
designed and manufactured (Fig. 7). It must be installed
close to the measurement dynamic region in order to
optimize the LC resonant circuit. Surface mount devices
were carefully selected, and the board size was minimized in order to decrease the magnetic field distortion
caused by the magnetization of the board.

Fig. 7. Newly developed read out board. Two older boards are also shown at the bottom.

Information System

Overview
The Information System Section plans, designs,
manages and operates the network infrastructure of
J-PARC and also provides support to ensure its information security. In terms of computing, until now, J-PARC
has owed its major computer resource for analyzing

and storing data from neutrinos, nuclear physics and
MLF experiments to the KEK central computer system.
The section connects the J-PARC network to the KEK
central computing system directory and helps the users
to utilize the system effectively.

Status of Networking
Since 2002, the J-PARC network infrastructure,
called JLAN, has been operated independently fromKEK LAN and JAEA LAN in terms of logical structure andoperational policy. In 2020, the total number of hosts

on JLAN exceeded 5,600, which was a 106% increase
compared to the last year. The growth curve of edge
switches, wireless LAN access points and hosts (servers
and PCs) connected to JLAN are shown in Fig. 1.

Information System

J-PARC Annual Report 2020

38

400
350
300
250
200
150
100
50
0

and 5 show the statistics of data transfer between the
Tokai site and the Tsukuba site. The network bandwidth
capacity between the two sites is 10 Gbps. This showsthat the usage level has been approaching a half of it,
especially during the period when the Hadron facility
was running. In addition to the current bandwidth, theupgrade offers a future option of 20 Gbps for both ofinternet and Tokai-Tsukuba connections, if the J-PARC
network can be adapted.

Edge Switches
WLAN Access Points
No. of hosts

6000
5000
4000
3000
2000
1000
0

Fig. 1. Number of hosts, edge SW and wireless AP on JLAN.

Fig. 2. Network traffic from JLAN to the internet.
(1 hour average and 5 minutes peak value)

Fig. 3. Network traffic from the internet to JLAN.

No. of Hosts connected to
JLAN

SW

and WLAN AP

In April 2016, the National Institute of Informatics(NII) upgraded SINET (Japan Science Information
Network https://www.sinet.ad.jp) from version 4 to 5.
SINET is not only a gateway from JLAN to the internet
but also an important connection between Tokai and
the KEK Tsukuba site in J-PARC.
Figures 2 and 3 show the network utilization of theinternet from/to JLAN. Since the bandwidth capacity forthe internet through the SINET is 10 Gbps, it is clear that
there is enough space for additional activity. Figures 4

J-PARC Annual Report 2020

Information System

39

Fig. 4. Network traffic from the Tsukuba site to the Tokai site.

Fig. 5. Network traffic from the Tokai site to the Tsukuba site.

Fig. 6. Peak network traffic for the recent years.

Internet Connection Services for Visitors andPublic Users of J-PARC
Since 2009, J-PARC has offered a Guest network(GWLAN) service, which is a wireless internet connection service for short-term visitors, available in almost
all J-PARC buildings. In the end of 2014, additional network service called User LAN has started. To use the
GWLAN, users are required to receive a password at the
J-PARC Users Office beforehand, while in the User LAN,
they are authenticated by the same ID and password
for the User Support System, which is also used for dormitory reservation and so on. From March 2016, a newservice called “eduroam” has been started. The eduroam (https://www.eduroam.org/) is a secure roaming
access service developed for the international researchand education community and mutually used among
a huge number of research institutes, universities,
and other institutions around the world. The eduroam
service will be a convenient third option of internet
connection service for J-PARC visitors. Figure 7 shows
this fiscal year’s usage statistics of GWLAN, User LAN
and the newly introduced eduroam service.

Information System

J-PARC Annual Report 202040

Fig. 7. Usage trends of GWLAN, User LAN and eduroam.

Status of Computing
Since J-PARC does not have computing resources
for physics analysis, starting from 2009, the KEK centralcomputing system (KEKCC) at the KEK Tsukuba campus
has been mainly used for that purpose. KEKCC is sharedby most of the research groups of KEK, including J-PARC.
At the Neutrino (T2K), Hadron and Neutron (MLF) experiments, the data taken in J-PARC are temporarily saved
at their facilities and then promptly transferred, stored,
and analyzed at the system in Tsukuba. The storage ofthe system is also utilized as a permanent data archivefor their data. The third upgrade of the system was completed in 2020, and the computing resources are shownin Table 1. Figures 8-10 show the utilization statisticsof the computing resources in FY2020. The main users
who used the CPU and storage constantly were fromthe Hadron and Neutrino experiment groups. The MLF
group also started to store data to tapes on the system.

%

Table 1. Computing resources in the KEKCC.

CPU (Intel Xeon Gold 6230)

15000 cores

RAID Disk (GPFS)

25.5 Peta Bytes

Tape Library (HSM)

100 Peta Bytes

CPU Utilization

100
80
60
40
20
0

HadronNeutrino

MLF

Other KEK users

Fig. 8. CPU usage statistics of KEKCC in FY2020.

J-PARC Annual Report 2020

Information System

41

Disk utillization in FY2020

4.0

2.0

PBytes

PBytes4.0

0.0

Disk annual utilization

2.0

0.0
HadronNeutrino

MLF

HadronNeutrino

MLF

10
9
8
7
6
5
4
3
2
1
0

Tape utilization in 2020
PBytes

PBytesFig. 9. Disk usage statistics (left: trend of FY2020; right: annual trend).

HadronNeutrino

MLF

10
9
8
7
6
5
4
3
2
1
0

Tape annual utilizaion

HadronNeutrino

Fig. 10. Tape library usage statistics (left: trend for FY2020, right: annual trend).

MLF

Transmutation Studies

Overview
We are developing nuclear transmutation technology with accelerator-driven systems (ADS) using
the J-PARC’s research resources and expertise in highpower accelerator and target technologies. The ADS isan effective nuclear system for volume reduction andmitigation of harmfulness of high-level radioactive
waste produced in nuclear reactors. We believe that
the ADS is one of the most beneficial applications ofhigh-power accelerators for contributing to humansociety.
The baseline design of the J-PARC Transmutation
Experimental Facility (TEF) was completed in FY2017(JAEA-Technology 2017-003 and 2017-033). To makethe facility more attractive and effective by introducing
leading edge knowledge to its purpose and specifications, we are changing the concept of the TEF to a newone. The main purpose of the new facility is to acquire

irradiation damage data of ADS’s beam window materials by impinging a proton beam to a lead-bismuth
eutectic target in which the sample materials arelocated. In addition, it is under consideration to irradiate the beam window and target materials used inhigh-power accelerator facilities, such as J-PARC, by
the proton beam directly to acquire irradiation dataof the materials to ensure a safe and efficient operation of those facilities. We also plan to equip the newfacility with a hot laboratory for efficient post-irradiation examination (PIE). Accordingly, it is expected thatthe new facility can contribute not only to the development of ADS but it will also help to upgrade the
J-PARC’s existing facilities.
As for the R&D activities on the lead-bismuth eutectic (LBE) target technology, we successfully establishedautomatic control of the oxygen concentration in LBE,

Transmutation Studies

J-PARC Annual Report 202044
and this enabled us to launch in November 2020 a
series of materials corrosion test campaigns using the
OLLOCHI LBE loop.
Our recent R&D activities on nuclear data for
nuclear transmutation received the following awards:• H. Iwamoto, S. Meigo, “Unified description of the fission probability for highly excited nuclei”, Academic
Award of Nuclear Data Subcommittee, Atomic Energy
Society of Japan (AESJ)• K. Nakano, “Isotope production in proton- and deu93
93
teron-induced spallation reactions on Zr and Nb”,
Incentive Award of Nuclear Data Sub-committee,
AESJ• H. Matsuda, S. Meigo, Y. Iwamoto, et al., “Measurementof displacement cross-sections of copper and iron for
proton with kinetic energies in the range 0.4 – 3 GeV”,
J. Nucl. Sci. Tech. 57, 1141 (2020), Treatise Award of
AESJ (Fig. 1)• S. Meigo, et al., “Experimental study on displacement cross section of structural materials for nuclear
transmutation systems”, Exploit R&D Award of JAEA’s
President Award
In addition, we issued two press releases:• “How much are metals damaged by high-intensity
proton beam irradiation?”, July 2020
• “Development of proton beam controlling

technology for nuclear transmutation research”,
December 2020

Fig. 1. Members of the Treatise Award of AESJ, Drs. Y. Iwamoto,
H. Matsuda, S. Meigo from the left.

On January 22, 26 and February 2, 2021, the seventh TEF Technical Advisory Committee (T-TAC) was
held on-line. This year, the T-TAC was specifically asked
for an advice on the progress in the ongoing R&D activities from the viewpoint of ADS activities in the world.
The main conclusions of the T-TAC were as follows:“T-TAC congratulates for the recent start of the OLLOCHI
installation.” and “T-TAC considers the R&D works carriedout by J-PARC as valuable contributions to the international ADS community.”

Research and development
The management of the lead-bismuth eutectic,
which are highly corrosive under high temperature, is
one of the key issues of the ADS. To overcome the issue,
a new method of applying oxygen potential control
technique to form an oxide layer on the steel surface
has been tested. Various research activities, operationof spallation target mockup loop, preparation of thecorrosion database, and development of the LBE measurement sensors are underway.
OLLOCHI
Oxygen concentration (OC) control tests in
OLLOCHI (Oxygen-controlled LBE LOop Corrosion tests
in High-temperature) started in January 2020 and we
managed to maintain the OC automatically within acertain range by mixing inlet gases. We started the firstcampaign of the long-term corrosion test in November
2020 and finished in February 2021. The total operation
period was about 2,000 hours. The test conditions wereas follows; the maximum temperature and the temperature difference were 450˚C and 100˚C, respectively.
The flow rate was about 1 m/s at the samples’ position.
-6
OC was kept at 1 × 10 wt%. Tested samples were takenout from the specimen holders shown in Fig. 2 and arebeing observed.

Fig. 2. Outline of specimen holders after the corrosion test
operation.

J-PARC Annual Report 2020

Transmutation Studies

45
IMMORTALIMMORTAL is a mock-up test loop of a future LBE
spallation target in TEF-T. Several modifications were
progressed to enhance the operability and the thermal
stability of the loop. In addition, the number of measurement points were increased by the modifications.
In the future, a transient heat-transfer experiment of
LBE under non-isothermal condition will be performed
after the evaluation test of the modified components.
LAPIN
LAPIN (LBE Apparatus for Purification of Impurities
by Natural convection) is a small LBE loop to understandthe natural convection behavior of LBE and evaluate
mixed impurities behavior. The LBE inventory is limited
to less than 8 liters, and it can be easily exchanged toapply various impurities in LBE. The temperature difference of LBE along the triangle flow channel is generated
by a heater unit and an air-cooled heat exchanger. As
a representative impurity, Ni will be applied because
its large solubility can cause various harmful effects
on the loop operation. In near future, the behavior of
LBE flow velocity and the oxygen concentration will be
evaluated.

NALTO
To develop electromagnet flow velocity probe(EM probe) for LBE, a rotating test apparatus named
NALTO (Nimble velocity measurement Apparatus in
LBE with controlled Temperature and Oxygen potential) was newly designed and installed. Figure 4 showsthe exterior of NALTO. It consists mainly of a chamber
containing a rotating annular vessel, gas atmosphere
control system and vessel rotating system. Because therigid body rotation of the LBE can be assumed, molten
LBE in the vessel rotates together with the vessel. Then,
we obtain the circumferential velocity of the LBE fromthe rotation speed of the vessel.

Fig. 4. Exterior of NALTO

Fig. 3. Exterior of LAPIN

Prototype EM probe was applied to the high temperature LBE. As a result, we obtained successfullya clear linearity between the velocity and the output
voltage from the probe up to about 500˚C, which was
higher than Currie temperature of the permanent magnet and suitable for the LBE spallation target operation.
To obtain the local flow direction, multi-velocity components will be measured with 4-electrodes type EM
probe in FY2021.

Research and development
Measurement of nuclide production cross sections
For predicting the radioactivity of the components
of ADS and their nuclear inventory calculation, nuclide
production cross sections play a vital role. We have
newly measured nuclide production cross sections inhigh energy proton-induced reactions on heavy nuclei,
165
nat
nat
209
such as Ho, Lu, Re, and Bi, by using the activation method as a part of a systematic measurement of

the cross-sections.
The irradiation experiment was performed at 3NBT.
The stacked metal foils were irradiated by 0.4, 1.3, 2.2,
and 3.0 GeV protons. After the irradiation, gamma-ray
measurement was performed for three months. The
production cross sections were derived from the decay
curve of the detected gamma-rays.
We identified the production of 44 nuclides for theTransmutation Studies

J-PARC Annual Report 2020

46
209

Bi target, including nuclides whose cross-sections
have never been measured, and successfully obtained
114 production cross-sections in all incident energy
206
regions. Figure 5 shows the Po production crosssection from the proton-induced reaction on Bi as afunction of incident proton energy. Our data support
Titarenko's data. The calculation using INCL4.6 and GEM
models shows excellent agreement with the measured
data.

Fig. 5. 206Po production cross section from the proton-induced
209
reaction on Bi.

Nuclear data measurement for ADS
An experimental program on nuclear data forresearch and development of ADS was launched in
2019, entrusted by MEXT. In the framework of this program, neutron energy spectrum measurements havebeen conducted using the Fixed-Field Alternating
Gradient (FFAG) proton accelerator at Kyoto University(Fig. 6). As the first experiment, we measured the double-differential thick target neutron yields (TTNY) anddouble-differential cross-sections (DDX) for an irontarget, which is the major constituent material of ADS,
using 107-MeV proton beams accelerated from the
FFAG accelerator. The preliminary results show that wehave successfully obtained the angle-dependent neutron energy spectra. As a next step, we will continue tomeasure the TTNY and DDX, focusing on lead and bismuth targets, which are essential materials for the ADS.

Proton accelerator for ADS
The Accelerator-driven subcritical system (ADS)
requires strict control of the number of beam trips to
avoid thermal stress in the beam windows. To this end,
the proton accelerator for ADS pursues a robust beam
optics design, Fault-tolerance capabilities, and repairability to become a reliability-oriented accelerator.
This work investigated the Fault-tolerance compensation schemes (FTCS) to reduce the system downtime
and consequently to allow the accelerator to reach thereliability requirements for a JAEA-ADS machine.
Fault-tolerance is accomplished by using the none
Faulty-element to counteract the unwanted effect of
the Faulty-element. Figure 7 top shows the readjustment of the accelerating gradient (Eacc) to compensate
for a failure in the last five-cell Elliptical cavity resonator
1 (EllipR1). The energy recovery is shown in the bottom
plot in Fig. 7.
The results showed that the FTCS for SRF cavities
and magnets produced acceptable beam performance,
except for the Half-wave Resonator (HWR) region, thefirst SRF section of the linac. Thus, these studies showed
the capability of FTCS for fast recovery in the rest of the
proton accelerator to satisfy the reliability requirements
for the ADS project.

Fig. 7. TCS for the failure in the last EllipR1’s cavity. The black
dotted vertical line indicates the transition between the
EllipR1 and EllipR2 regions.

Fig. 6. FFAG accelerator.

J-PARC Annual Report 2020

Transmutation Studies

47

MA Irradiation Experiments

Fig. 8. Photograph of the JAEA single fission chamber.

10000

U-235
Np-2371000
C ounts

To develop an accelerator-driven system (ADS), it isnecessary to verify the nuclear data of minor actinides(MAs) in a fast neutron core, such as the transmutation physics experimental facility (TEF-P) designed in
J-PARC. As planned in TEF-P, one of the verifications
is to use fission chambers containing MA as fission235
able material and a well-known material such as U
as reference in the critical or sub-critical core, where
the neutron spectrum in ADS core can be simulated.
To achieve high-accuracy verification, precise fabrication of the chamber (e.g. accountancy and purity ofMA, uniformity of MA layer, and hermeticity) is important, but the fabrication itself requires R&D because
the preparation of pure raw MA and its treatment are
possible in very limited facilities. We have recently
237
fabricated several chambers (Fig. 8) containing Np,
241
243
244
Am, Am, or Cm in NUCEF in JAEA and measured
237
235
243
235
the ratios of the Np/ U and Am/ U fission rates
at the Kyoto University Critical Assembly (KUCA).
Figure 9 shows the pulse height distributions of237
235
Np and U fission reactions as an example. The fis237
235
243
235
sion rate ratios of Np/ U and Am/ U obtainedby each pulse height were 0.048 ± 0.003 and 0.042 ±0.004, respectively. According to the tentative calcula237
235
tions, the result of Np/ U was in good agreement
243
235
with the measurement, but the result of Am/ U
underestimated the measurement. These experimental data were obtained with high accuracy and would
be usable for verification of evaluated nuclear data byconducting detailed analyses [1].

100
10
1

0

1

2
P uls e height (V )3

4

Fig. 9. Fission signals of the 237Np and 235U fission chambers[1]

Reference[1] A. Oizumi et al., KURNS Progress Report 2020, (2021).

Transmutation Studies

J-PARC Annual Report 2020

48

International and Domestic Cooperation
In spite of the severe restrictions due to the COVID19, we proceeded steadily with the international
cooperation.
We are collaborating closely with the Belgian
Nuclear Research Centre (SCK CEN) for the ADS
development under the collaboration arrangement
between SCK CEN and JAEA. SCK CEN is promoting
the MYRRHA (Multi-purpose hYbrid Research Reactor
for High-tech Application) project, which is the world’s
first large scale ADS project at power levels scalable
to industrial systems. There are three important topics of cooperation, i.e., neutronics, LBE technology and
ADS’s accelerator development. As for the neutronics,
experimental data obtained at J-PARC, such as protoninduced nuclide production cross section and neutron
spectral flux intensity from the MLF’s mercury target,
were shared with SCK CEN for validating the neutronics calculation codes. In the case of the LBE technology,
the performance of the oxygen sensors produced by
SCK CEN was compared with that of JAEA’s oxygen
sensors. It was found that the sensors produced by thetwo institutes indicated a consistent and valid output.
As for the ADS’s accelerator development, one young
scientist of the J-PARC’s Linac team, Dr. Jun Tamura,visited Louvain-la-Neuve in Belgium from January to
December 2020. He joined the MYRRHA accelerator
team and contributed to producing a prototype of the
MYRRHA linac of up to 100 MeV (Fig. 10).
In addition, “Arrangement in the field of nuclear
research as pertaining to accelerator driven systems and their safety” between Karlsruhe Institute ofTechnology (KIT) in Germany and JAEA was agreed
upon on June 18, 2020. An on-line meeting between
KIT and JAEA was held on October 8, 2020 where thetwo parties agreed on the Specific Topic of Cooperationin the field of the LBE technology.

Fig. 10. Dr. Jun Tamura working with the MYRRHA accelerator
team at Louvain-la-Neuve, Belgium.

On March 30 and 31, 2021, two on-line workshops
related to the J-PARC’s irradiation facility were held.
In the first workshop, possibilities of the J-PARC’s irradiation facility were discussed. The most importantmessage was that “the J-PARC’s facility will be very
effective not only for materials irradiation research but
also for education of young scientists under the current situation when the number of research reactors
is decreasing.” The second workshop was focused on
the soft error of semiconductor devices, which would
be one of the important themes to be studied by using
the intense high-energy neutron beam from the LBE
target. It was concluded that the J-PARC’s facility would
provide a very suitable soft error test environment
because its flux intensity is the highest in the world.

SafetySafety

J-PARC Annual Report 2020

50

Safety1. Major events on safety culture and safety activities in the J-PARC
Through our experiences of the various accidents
and incidents, the J-PARC has reaffirmed that “Thesafety of the facility is achieved by the efforts of every
person involved”, and we actively implement safety
culture development activities to upgrade the safety
awareness and skills of each person. Our efforts toenforce the safety culture in the J-PARC include sharing
safety information, enhancement of safety awareness,
education and training, etc. For these purposes, newapproaches are being introduced sequentially. In addition, these activities are being reviewed internally andby external experts to ensure continuous improvement.
In fiscal year 2020, responding to the global outbreak of the novel coronavirus (COVID-19), the annual
safety policy was determined as “Creating work safety
style that incorporates new lifestyles.” On the basis of
this policy, we tried to effectively and flexibly integrate
the anti-COVID-19 measures with the normal safetymeasures. In order to prevent the increase of potential
risks such as heatstroke, fires, falls, etc. when focused
too excessively on infectious disease countermeasures,
we continued steadily the safety activities that we havebeen conducting so far, such as sharing good practices
and commendation, experience-based safety trainings, e-learning on safety issues, certification training
for radiation measurement technique, sharing of safety
information using video materials, etc. In addition, we1
newly introduced the “KY” training to promote proactive and creative efforts in the workplaces and to
improve the skills on safety matters.
Table 1 lists the major events on safety culture
and safety activities in the J-PARC. The J-PARC Center
had held “the J-PARC Safety Day” around May 23, thedate when the radioactive material leak incident
occurred in 2013. However, due to concerns related
to COVID-19, Safety Day 2020 was postponed andheld on September 9 online. Following the introductory talk by the J-PARC director, some good practices
related to safety and health were awarded. The maintalk entitled “Introduction to occupational behavior
analysis” was given by Dr. Rieko Hojo (National Instituteof Occupational Safety and Health, Japan). Further, a
1 “KY” is a Japanese word meaning a briefing in which workers
discuss and confirm the potential risks in their work shortly before
it starts. “KY” is an abbreviation of “Kiken Yochi” meaning “Hazard
Prediction.”

newly produced video on the radioactive material leakincident in 2013 was presented.
An emergency drill was conducted on October 21
at the Hadron Experimental Facility (HD) by supposingthat the beam operation was started when two workers were left in the experimental area of HD. The drill
included transportation and decontamination of the
exposed workers, estimation of exposure doses, setupof the command post and communication with theaccident site, report to the headquarters via TV conference, and a simulated press release.
The J-PARC safety audit in fiscal year 2020 was conducted by two auditors on December 7. They reviewed
the following points: 1) Organization of safety management, 2) Management of work safety, 3) Emergency
preparedness, and 4) Safety education and promotion and continuation of the safety culture. An on-site
inspection of the works at the MLF facility was also
conducted. The auditors gave us valuable recommendations on safety measures with considerations for thedevelopment of the J-PARC over the next 10 years.
2. Radiological license update and facility inspection
Applications to update the radiological license
were submitted to the Nuclear Regulation Authority on
October 5. Table 2 lists the main changes in the applications. The permit for the applications was issued onJune 9, 2021.
The facility inspection for the construction of a new
High-p beamline at the Hadron Experimental Facility
and the associated change with the shielding structure, which was applied for on December 6, 2019, andapproved on April 28, 2020, was conducted on June 22,2020, as part of the regular inspection, and passed onJune 24, 2020.
3. Meeting of the committee on the radiation safety
matters
The J-PARC Radiation Safety Committee is organized as an advisory committee to both JAEA and KEK
to discuss the policy on radiation safety in the J-PARC.
Meanwhile, the Radiation Safety Review Committee has
been established to discuss specific subjects of radiation safety in the J-PARC.
In FY2020, the J-PARC Radiation Safety Committee
met twice, and the Radiation Safety Review Committee
met three times. Table 3 lists the major issues for thecommittees.

J-PARC Annual Report 2020

Safety51
4. Radiation exposure of radiation workers
The number of persons subject to annual measurement of external exposure in FY2020 was 2,705 due toa decrease in the number of users engaged in radiation
work due to the impact of the spread of the new coronavirus infection.
Table 4 lists the distribution of annual exposed

doses for each category of workers. There was no exposure exceeding the dose limit specified in the local
radiation protection rule for the J-PARC and the administrative dose limits (7 mSv/year) specified in the detailed
rule of local radiation protection rule for the J-PARC. The
total annual effective dose was 27.1 person·mSv, andthe maximum effective dose was 0.9 mSv.

Table 1. List of major events on safety in FY2020.

Day

EventsJune 30, 2020

Liaison committee on safety and health for contractors

September 9, 2020

Safety Day (Meeting to exchange safety information between each section, Workshop
for fostering safety culture)

October-December

Refresher course on radiation safety for in-house staff (e-learning)

October 21,2020

Emergency drill assuming while the workers were in the Hadron experimental area, thebeam was withdrawn, causing massive exposure

December 7, 2020

FY2020 J-PARC Safety Audit

January 7, 2021

KY training (Using an illustration sheet depicting the work situation, the participants
discuss, think about it, come to an understanding r about possible hazards and countermeasures, and finally confirm the action goal by pointing and calling.)

Table 2. Major application items of the radiological license.

Facility

Items of an application

MLF• Installation of the Fast Muon Experimental Facility• Expansion of the Slow Muon Experimental Facility

NU• Addition of the drainage system (storage tank)

AII• A change of the site boundary of the J-PARC

Safety

J-PARC Annual Report 2020

52
Table 3. Radiation Safety Committee (RSC) and Radiation Safety Review Committee (RSRC) in FY2020

No.

Date

Major Issues

The Radiation Safety Committee
35th

August 6, 2020

• The policy for radiological license update in FY2020

36th

March 22, 2021

• The proposal to increase the beam intensity from the original plan
• The plan for radiological license update in FY2020

The Radiation Safety Review Committee
27thJuly 29, 2020

• Update of the radiological license for the Neutrino facilities• Installation of an X-ray generator• Revision of the local radiation protection rule of the J-PARC

th

October 16, 2020

• Revision of the detailed rule of local radiation protection rule for J-PARC.
• The policy for revision of the operational rulesthMarch 12, 2021

• Update of the radiological license for the Neutrino facilities• Installation of an X-ray generator

28
29

Table 4. Annual exposed doses in FY2020# ofworkers

Dose range x (mSv)
ND

0.1≤ x ≤1.0

1.0< x ≤5.0

5.0< x

Collective dose
(person · mSv)

Maximum dose(mSv)

In-house staff

680

648

32

0

0

9.0

0.7

Users

717

717

0

0

0

0.0

0.0

Contractors

1,315

1,250

65

0

0

18.0

0.9

Total

2,705

2,608

97

0

0

27.1

0.9

User Service

User Service

J-PARC Annual Report 2020

54

Users Office (UO)
Outlinetration as a J-PARC User, radiation worker registration,
safety education, accommodation, visa invitation letter and other requirements. Then, the UO staffs provide
them with support by e-mail. After their arrival at the JPARC, the UO provides on-site assistance to the J-PARC
Users, like receiving the J-PARC ID, glass badge, andsafety education. Since 2015, the UO had been doing its
part to improve the J-PARC on-line experiment system
and make it more user-friendly.
After completion of the experiments, the UO may
return the experiment samples at User’s cost after cooling the radioactive materials.

The J-PARC Users Office (UO) was established in2007. It opened an office on the first floor of the IBARAKI Quantum Beam Research Center in Tokai-mura, in
December 2008. The UO maintains the Tokai Dormitory
for the J-PARC users. The UO provides on-site and WEB
support with one-stop service for the utilization of the
J-PARC. As of March 31, 2020, the UO had 12 staffs and
6 WEB Support SE staffs in the Users Affairs Section. The
J-PARC Users, after the approval of their experiment,
follow the administrative procedures outlined on theUsers Office (UO) WEB Portal Site, related to their regis-

1 Hitachi
Minami-ohta

Tokai Campus
Niken-jaya
intersection

TOKAI
Smart IC

J-PARC Users Office

Tokai Village
OfficeJAEA Main Gate
(Central Security Office)[J-PARC]

Cocos
restaurant
62

PC depostore

Kakeagariintersection

Post Office

Tokai Hospital

JR Tokai
StationMobile phone
shop

Muramatsu
ShrineFire Station

Joban
Expressway

Magome-jujiro
intersection
349

Kasamatsu
Park

Ibaraki Higashi
National Hospital
245

Macdonald
Humbugger Shop
Lawson31

JR JobanLine

Naka-city Hall

3
2

Naka

Hitachinaka

Higashi MITO Expressway

Map to the J-PARC Users OfficeJ-PARC Annual Report 2020

User Service

55

Activities of the UO

J-PARC Users

Technical
contact
personTechnical
supportResearch
Proposal

J-PARC Users Office
Procedures for
J-PARC site access• ID card• Portal site
• Rental goods

Proposal
Advisory
Committee

Support Service
for Daily Life

Support for
J-PARC Utilization• Accomodation• Rent-a-car• Living information• User room
• Radiation/Facility
safety education

One stop service for J-PARC users

on the web
Step 1

on-site support

User registration

New user

Registered user

Getting user ID

Annual registration, specifyingof the visit

Approval of UO

Step 3
Procedures upon arrivalat the first day
Recieve J-Parc User ID card
Vehicle Permission pass

Step 2-1 Obligatory application
Application form to visit J-PARC
Visit proposal (foreign nationality)
Reservation of safety training
On-line education video

Step 2-2

Optional application

J-PARC Card for facility accessNetwork registration
Radiation worker registration
Reservation of Dormitory
Invitation letter for Visa

Safety education and dosimeter

Users Office at IQBRC

Office hours(9:00-17:00, Mon.-Fri.)

Rental goods
BicylePHS
Cafeteria card
Locker key
Office key

Rental bicycle

Step 4 J-PARC Experiment and meeting
Step 5 Leaving procedures
Retern all cards, keys, rental goods UO(office hours) or return box!

Return box at IQBRC

User Service

J-PARC Annual Report 2020

56

User Statistics
Users in 2020 (Japanese ⁄ Foreigners, person-days)
3,500
3500

Foreigners
Japanese

3,000
3000
2,500
2500
2,000
2000
1,500
1500
1,000
1000
500
500
00

4
2020

5

6

7

8

9

10

11

12

1
2021

2

3

Users in 2020(according to facilities, person-days)

Users in 2020(according to organizations, person-days)

Accelerator
554

Foreign Organizations
857
PrivateEnterprises
753

Neutrino
1,621

Other 23

PublicOrganizations
1,619
MLF
8,387
Japanese
Universities
13,232

Hadron5,922

HadronMLF

Neutrino

Japanese Universities
Foreign Organizations

Accelerator（人日）

Public Organizations
Other

Private Enterprises

（人日）

2,500
2500

3,000
3000
2,500
2500

2,000
2000

2,000
2000

1,500
1500

1,500
1500

1,000
1000

1,000
1000

500
500

500
500

3

2

.1

12

21
20

11

9

10

8

7

6

5

.4
20
20

3

2

.1

12

21
20

11

9

8

7

6

10

20
20

5

00
.4

00

User Service

J-PARC Annual Report 202057

MLF Proposals Summary - FY2020
Due to the COVID-19 situation, 2020B and 2021A were combined into one proposal round. The experiment period
for the proposals for “2020B+2021A” was from December 2020 to July 2021. Therefore, the proposals for 2021A are
included in the FY2020 data as they cannot be counted separately.
Table 1. Breakdown of Proposals Numbers for the 2020 Rounds
Beamline

2020A

Submitted Approved Submitted Approved

Instrument

BL01

4D-Space Access Neutron Spectrometer - 4SEASONS

BL02

Biomolecular Dynamics Spectrometer - DNA

BL03

IBARAKI Biological Crystal Diffractometer - iBIX

2020B + 2021A(100-β)(β)‡†

Full Year
Submitted

Approved

GU

GU

GU

GU

PU/S

IU

PU/S

IU

25(0)

10(0)

31(0)

11(0)

0

1

0

1

24(0)

5(0)

36(2)

15(1)

2

2

2

2

0

0

3

3

0

0

0

0

0

0

0

0

48 ※

0

47 ※

0

BL04

Accurate Neutron-Nucleus Reaction Measurement Instrument - ANNRI

5

4

11

5

1

1

1

1

BL05

Neutron Optics and Physics - NOP

2

2

4

4

1

0

1

0

BL06

Village of Neutron Resonance Spin Echo Spectrometers - VIN ROSE

1

1

7

4

1

0

1

0

BL08

Super High Resolution Powder Diffractometer - SuperHRPD

13

8

19

11

1

0

1

0

BL09

Special Environment Powder Diffractometer - SPICA

2

2

1

1

1

0

1

0

BL10

Neutron Beamline for Observation and Research Use - NOBORU

10

7

15

10

3

1

3

1

BL11

High-Pressure Neutron Diffractometer - PLANET

21(0)

15(0)

14(0)

12(0)

0

1

0

1

BL12

High Resolution Chopper Spectrometer - HRC

5

4

11

8

1

0

1

0

BL14

Cold-Neutron Disk-Chopper Spectrometer - AMATERAS

25

8

36

7

3

1

3

1

BL15

Small and Wide Angle Neutron Scattering Instrument - TAIKAN

35(0)

15(0)

50(2)

20(2)

2

3

2

3

BL16

Soft Interface Analyzer - SOFIA

14

14

29

25

0

1

0

1
3

BL17

Polarized Neutron Reflectometer - SHARAKU

18(2)

11(1)

20(1)

14(1)

2

3

2

BL18

Extreme Environment Single Crystal Neutron Diffractometer - SENJU

18(0)

9(0)

28(0)

10(0)

1

1

1

1

BL19

Engineering Materials Diffractometer - TAKUMI

14

11

31

21

1

1

1

1

BL20

IBARAKI Materials Design Diffractometer iMATERIA(100-β)
(β)

‡

†

9

6

8

6

0

0

0

0

26

26

36

36

22

0

22

0

BL21

High Intensity Total Diffractometer - NOVA

25

19

20

10

1

0

1

0

BL22

Energy Resolved Neutron Imaging System - RADEN

10(0)

10(0)

24(0)

16(0)

2

3

2

3

BL23

Polarized Neutron Spectrometer - POLANO

1

1

2

2

1

0

1

0

D1

Muon Spectrometer for Materials and Life Science Experiments - D1

15(0)

6(0)

20(0)

12(0)

1

1

1

1

D2

Muon Spectrometer for Basic Science Experiments - D2

3(1)

3(1)

8(0)

4(0)

1

1

1

1

S1

General purpose µSR spectrometer - ARTEMIS

22(2)

16(2)

46(0)

24(0)

1

1

1

1

U1A

Ultra Slow Muon Microscope - U1A

0

0

0

0

0

1

0

1

U1B

Transmission Muon Microscope - U1B

0

0

0

0

0

1

0

1

343

213

509

290

87

24

86

24

Total

GU : General Use
PU : Project Use or Ibaraki Pref. Project Use
S : S-type Proposals
IU : Instrument Group Use† : Ibaraki Pref. Exclusive Use Beamtime (β = 80% in FY2020)‡ : J-PARC Center General Use Beamtime (100-β = 20% in FY2020)( ) : Proposal Numbers under the New User Promotion (BL01, BL02, BL11, BL15, BL17, BL18, BL22) or
P-type proposals (D1,D2, S1) in GU※ Proposal rounds are held twice per year (for each of the A and B periods), with only the yearly total shown above.
The actual total number of proposals in each beamline named in the table does not match the number shown in the “Total” cell,because some proposals are submitted or approved across multiple beamlines.

User Service

J-PARC Annual Report 2020

58
Table 2. Proposals Numbers of Long Term Proposal for the 2020 Rounds
Application FY

Submitted

Approved

2018

9

5

2019

9

4

2020

13

3

1000
800

329

360

Proposals

199
600

142

400

0

34
67

45

309

214

293

460

422

Not Approved

231

Approved

395
126

42
20

200

278

607

507

469
321

255

630

616

353

FY2008 FY2009 FY2010 FY2011 FY2012 FY2013 FY2014 FY2015 FY2016 FY2017 FY2018 FY2019 FY2020

Proposal RoundFig. 1. MLF Proposal Numbers over Time

CROSS
KEK
44
42
5%
4%
JAEA
78
8%

Universities (Japan)
Companies (Japan)

Foreign Organizations
238
24%

Universities (Japan)
404
41%Research Institutes (Japan)
Foreign Organizations
JAEA
KEK
CROSS

Companies (Japan)
132
14%
Research Institutes (Japan)
38
4%Fig. 2. Origin of Submitted Proposals by affiliation - FY2020 (2020A, 2020B+2021A)

P9
7
1%

Q1
58
8%

Q2
55
7%

P1
70
9%

P1: Structural Science (Crystal, Amorphous and Liquid)
P2
85
11%

P8
62
8%

P2: Energy Science and High-Pressure Science
P3: Soft Matter and Biologocal Matter
P4: Magnetic Material and Strongly Correlated Electron System (Structure)
P5: Magnetic Material and Strongly Correlated Electron System (Dynamics)

P3
114
15%

P7
55
7%
P6
57
8%

P5
109
14%

P4
90
12%

P6: Fundamental Physics, Nuclear Physics, Instrumentation, Imaging
P7: Industrial Application
P8: Materials Engineering
P9: New User Promotion
Q1: Electronic Properties of Matter & Hydrogen in Matter
Q2: General Applications

Fig. 3. Submitted Proposals by Sub-committee/Expert Panel –2020 (2020A, 2020B+2021A)

J-PARC Annual Report 2020

User Service

59

J-PARC PAC Approval Summary for the 2020 Rounds
E03
P04

(Co-)
Affiliation
Title of the experiment
Spokespersons–
K.Tanida
JAEA
Measurement of X rays from X Atom
U of Illinois
J.C.Peng,
Measurement of High-Mass Dimuon Production at theat UrbanaS.Sawada
50-GeV Proton Synchrotron
Champaign; KEK
12
X

E05

T.Nagae

Kyoto USpectroscopic Study of X-Hypernucleus,
12–+
C(K , K ) Reaction

E06

J.Imazato

KEK

Measurement of T-violating Transverse Muon+
0+
Polarization in K -> p m n Decays

E07
E08
E10
E11
E13
E14
E15
E16
E17
E18
E19
E21
E22
T25
E26
E27
E29
E31
T32
P33
E34
E36

K.Imai,
JAEA, Gifu U,
K.Nakazawa,
Tohoku U
H.Tamura
A.Krutenkova ITEP

Be, via the

Approval status(PAC recommendation)
Stage 2

K1.8

DeferredPrimary

Stage 2New experiment E70 based on the
S-2S spectrometer

K1.8

E36 as the first step

K1.1BR

Systematic Study of Double Strangeness System with an
Stage 2
Emulsion-counter Hybrid Method

Beamline

K1.8

Pion double charge exchange on oxygen at J-PARC
Stage 1K1.8
Production of Neutron-Rich Lambda-Hypernuclei with
Osaka U, Osaka
the Double Charge-Exchange Reaction (Revised from
Stage 2
K1.8
EC U
Initial P10)
A.K.Ichikawa,
Tokai-to-Kamioka (T2K) Long Baseline Neutrino
Stage 2
KEK
neutrino
F.Sanchez
Oscillation Experimental Proposal
H.Tamura
Tohoku U
Gamma-ray spectroscopy of light hypernuclei
Stage 2
K1.8
0
T.Yamanaka Osaka U
Proposal for KL -> p n n-bar Experiment at J-PARC
Stage 2
KL
M.Iwasaki,
A Search for deeply-bound kaonic nuclear states by inRIKEN, Kyoto U
Stage 2
K1.8BR
T.Nagaeflight 3He(K-, n) reaction
Measurements of spectral change of vector mesons in
nucleiS.Yokkaichi
RIKEN
Stage 2 for Run 0
High p(previously “Electron pair spectrometer at the J-PARC 50GeV PS to explore the chiral symmetry in QCD”)
R.Hayano,
Registered as E62 with an updated
3
U Tokyo, RIKEN Precision spectroscopy of Kaonic He 3d->2p X-rays
K1.8BR
H.Outaproposal
12
C
Coincidence
Measurement
of
the
Weak
Decay
of
H.Bhang,
SNU, RIKEN,
L
Stage 2K1.8
H.Outa, H.Park KRISS
and the three-body weak interaction process+––
High-resolution Search for Q Pentaquark in p p -> K X
M.Naruki
KEK
Stage 2
K1.8
ReactionsPhase-I Stage 2
An Experimental Search for μ − e Conversion at a
PAC recommends producing a more
Y.KunoOsaka U
COMET
−16
Sensitivity of 10 with a Slow-Extracted Bunched Beam detailed schedule to ensure a timely
start.
S.Ajimura,
Exclusive Study on the Lambda-N Weak Interaction in
Osaka U
Stage 1
K1.8
A.Sakaguchi
A=4 Lambda-Hypernuclei
Extinction Measurement of J-PARC Proton Beam at
S.Mihara
KEK
Test Experiment
K1.8BR
K1.8BRA
Search for w-meson nuclear bound states in the p-+ Z ->(A-1)
K.Ozawa
KEK
n+ w(Z-1) reaction, and for w mass modification in the Stage 1
K1.8
0
in-medium w->p g decay–+
Search for a nuclear Kbar bound state K pp in the d(p ,T.Nagae
Kyoto U
Stage 2
K1.8+
K ) reaction
A
Search for f-meson nuclear bound states in the pbar + Z
H.Ohnishi
RIKEN
Stage 1
K1.1
(A-1)-> f + f(Z-1) reaction
Spectroscopic study of hyperon resonances below KN
Stage 2
K1.8BR
H.NoumiOsaka U–
threshold via the (K ,n) reaction on DeuteronTowards a Long Baseline Neutrino and Nucleon Decay
Experiment with a next-generation 100 kton Liquid
A.Rubbia
ETH, Zurich
Test Experiment
K1.1BR
Argon TPC detector at Okinoshima and an intensity
upgraded J-PARC Neutrino beam
H.M.Shimizu Nagoya U
Measurement of Neutron Electric Dipole Moment
Deferred
Linac
An Experimental Proposal on a New Measurement of theT. Mibe
KEK, RIKEN
Muon Anomalous Magnetic Moment g-2 and ElectricStage 2MLF
Dipole Moment at J-PARC++++
Measurement of G(K -> e n)/G(K -> m n) and Search
M.Kohl,Hampton U,
Stage 2
K1.1BRfor heavy sterile neutrinos using the TREK detector
S.Shimizu
Osaka Usystem
A.Sakaguchi,
T.Fukuda

E40

K.MiwaP41

M.AokiE42

J.K.Ahn

E45

K.H.Hicks,
H.SakoT46
T49

K.Ozawa
T.Maruyama

Tohoku U

Measurement of the cross sections of Σp scatterings

Stage 2

K1.8

An Experimental Search for μ − e Conversion in Nuclear−14
Field at a Sensitivity of 10 with Pulsed Proton Beam
Deferred
MLF
from RCS
Pusan National Search for H-Dibaryon with a Large Acceptance Hyperon
Stage 2
K1.8
USpectrometer
Stage 2
PAC requests that the group further
3-Body Hadronic Reactions for New Aspects of Baryon
examine ways to reduce the total
Ohio U, JAEA
K1.8
Spectroscopy
beam time requested and to find an
efficient running scheme, including
quick but careful beam tuning.
KEK
EDIT2013 beam test program
Test Experiment
K1.1BR
KEK
Test for 250L Liquid Argon TPC
Test Experiment
K1.1BR
Osaka U

StatusData taking

Finished

Finished
Data analysis
Li run finished, Betarget run with
S-2S
Data taking
Finished
Data taking
Finished
Data taking

Finished

Finished

Fisnished

Finished
Data analysis
Finished

Finished
Data analysis
Finished
Data analysis
Reviewed in MLF/
IMSS

Abandonded
Withdrawn

User Service

J-PARC Annual Report 2020

60
(Co-)
Spokespersons

Affiliation

E50

H.NoumiOsaka U

T51

S.Mihara

KEK

Title of the experiment*–Charmed Baryon Spectroscopy via the (π, D ) reaction

Approval status
Beamline(PAC recommendation)
Stage 1The FIFC, IPNS, and E50 shouldHigh pinvestigate the beam-line feasibility

Research Proposal for COMET(E21) Calorimeter
Test Experiment
Prototype Beam Test
Test of fine pixel CCDs for ILC vertex detector
Test Experiment
Test of GEM Tracker, Hadron Blind Detector and LeadTest Experimentglass EMC for the J-PARC E16 experiment
Test experiment for a performance evaluation of ascattered proton detector system for the Σp scattering Test Experimentexperiment E40
Second Test of Aerogel Cherenkov counter for the
Test Experiment
J-PARC E36 experiment
A Search for Sterile Neutrino at J-PARC Materials and Life
Stage 2
Science Experimental Facility

K1.1BR

Statushad to be stopped

T52

Y.Sugimoto

KEK

T53

D.Kawama

RIKEN

T54

K.MiwaTohoku U

T55

A.Toyoda

KEK

E56

T.Maruyama

KEK

E57

J. Zmeskal

Stefan Meyer
Institute forSubatomic
Physics

P58

M. Yokoyama U. Tokyo

T59

A. Minamino

Kyoto U

T60

T. Fukuda

Toho U

E61

M. Wilking

Stony Brook U

E62

R. Hayano,S. Okada,
H. Outa

U. Tokyo, RIKEN Precision Spectroscopy of kaonic atom X-rays with TES

Stage 2

K1.8BR

Finished

E63

H. TamuraTohoku U

Gamma-ray spectroscopy of light hypernuclei II

Stage 2

K1.1

BL not readyyet. Exp. in
preparation

T64

Y. Koshio

Okayama U

Measurement of the gamma-ray and neutron
background from the T2k neutrino/anti-neutrino at
J-PARC B2 Hall

Arranged by IPNS and KEK-T2K

neutrino

E65

A.K.Ichikawa,
Kyoto U
F.Sanchez

Proposal for T2K Extended Run

Stage-2

neutrino

T66

T. Fukuda

Nagoya U

P67

I. Meigo

JAEA

T68

T. Fukuda

Nagoya U

E69

A. Minamino

Yokohama
National U

E70

T. Nagae

Kyoto U

E71

T. Fukuda

Nagoya U

E72

K. Tanida

JAEA

E73

Yue MaRIKEN

P74

A.Feliciello

INFN, Torino

E75

H.Fujioka

Tokyo Inst.
Tech,

P76

H.M.Shimizu

Nagoya U

T77

Yue Ma

RIKEN

T78
P79
P80

H.Nishiguchi
T.Ishikawa
F.Sakuma

KEK
Tohoku U
RIKEN

T81

T.Fukuda

Nagoya U

P82

T.Maruyama

KEK

Measurement of the strong interaction induced shift andStage 1width of the 1s state of kaonic deuterium at J-PARC

K1.1BRnot performed yet

K1.1BRnot performed yet

K1.1BRnot performed yet

K1.1BR

had to be stopped

MLF

Data taking

K1.8BRin preparation

A Long Baseline Neutrino Oscillation Experiment Using
Deferredneutrino
J-PARC Neutrino Beam and Hyper-Kamiokande
A test experiment to measure neutrino cross sections
neutrinousing a 3D grid-like neutrino detector with a water target To be arranged by IPNS and KEK-T2K monitor Finishedat the near detector hall of J-PARC neutrino beam-line
bld
neutrino
Proposal of an emulsion-based test experiment at
Arranged by IPNS and KEK-T2K
monitor Finished
J-PARC
bld
Superseded.
E61 has been adopted in Hyper-K as
NuPRISM/TITUS
neutrino
IWCD.
IWCD is reviewed by HK-PAC.

Proposal of an emulsion-based test experiment at
Test Experimentneutrino
J-PARC
Measurement of displacement cross section of proton in
Carry out the experiment within theenergy region between 3 and 30 GeV for high-intensityMRframework of facility development
proton accelerator facility
Extension of T60/T66 Experiment: Proposal for the Run
Test Experimentneutrinofrom 2017 Autumn
Study of neutrino-nucleus ineraction at around 1GeV
using cuboid lattice neutrino detector, WAGASHI, muon
Superseded. Merged with T2K.
neutrino
range detectors and magnetized spectrometer, Baby
MIND, at J-PARC neutrino monitor hall
Proposal for the next E05 run with the S-2S spectrometer Stage-2
K1.8
Proposal for precise measurement of neutrinop-water
Stage-2
neutrino Data taking
cross-section in NINJA physics run
Search for a Narrow Λ* Resonance using the p(K-, Λ)η
Stage-2
K1.8BR
Reaction with the hypTPC Detector
34
ΛH and ΛH mesonic weak decay lifetime measurement
Stage-1
K1.8BR
3,4– 0 3,4
with He(K ,π ) ΛH reaction
Direct measurement of the 3ΛH and 4ΛH lifetimes using
Rejected
K1.1
the 3,4He(π-,K0)3,4ΛH reactions
Decay Pion Spectroscopy of 5ΛΛH Produced byStage-1K1.8
Ξ-hypernuclear Decay
Searches for the Breaking of the Time Reversal Invariance
Deferred
MLF
in Polarized Epithermal Neutron Optics
Feasibility study for 3ΛH mesonic weak decay lifetime
PAC supoorts the ontinuation of T77
measurementby an explorative run with the 3He K1.8BR
with 3,4He(K-,π0)3,4ΛH reaction
target.
8GeV Operation Test and Extinction Measurement
Test Experiment
K1.8BR
Search for an I=3 dibaryon resonance
PAC suggests stage-1 status
High pSystematic investgatin of the light kaonic nuclei
PAC suggests stage-1 status
K1.8BR
Proposal of test experiment for technical improvementsof neutrino measurements with nuclear emulsion
Test Experimentneutrino
detector
JSNS2-II
PAC suggests stage-1 status
MLF

Organization and Committees

Organization and Committees

J-PARC Annual Report 2020

62

Organization Structure
J-PARC Center Management System Chart
as of April 1, 2020

Deputy Director(Safety)

T. Ishii

Safety Division

Radiation Control Section
Y. Nakane - M. Numajiri, K. Seki

Y. Miyamoto - K. Bessho, Y. Nakane

Safety Promotion Section
Y. Kasugai - T. Itoh

H. Oguri

K. Yamamoto

Accelerator Division
M. Kinsho - H. Oguri, F. Naito

N. Hayashi
M. Yoshii
T. Toyama
F. Naito

N. Saito

Director

K. Haga - K. Sakai

Deputy Director(JAEA)

M. Futakawa

Y. Kawakita - T. Yokoo, M. Nakamura

Materials & Life Science Division
T. Otomo - K. Aizawa, K. Nakajima
K. Simomura

K. Sakasai
R. Kadono - N. Kawamura
T. OkuDeputy Director(KEK)

T. Koseki

Director’s Oﬃce
Advisor (J-PARC) : S. Nagamiya
Advisor (J-PARC) : Y. Ikeda
Advisor (J-PARC) : Y. Fujii
Advisor (J-PARC) : M. Takasaki
Advisor (J-PARC) : T. Ohska
Advisor (J-PARC) : M. Kataoka
Advisor (J-PARC) : K. Hasebe

T. Nakadaira

T. Kobayashi - T. Komatsubara, Y. Fujii

Nuclear Transmutation Division

M. Futakawa - F. Maekawa

S. Sawada

T. Sasa
S. Meigo

Y. Makita - K. Sasaki

K. Gorai - J. Suzuki

H. Takada - M. Nomura

M. AbeY. Yamazaki - Y. Miyamoto
H. Koda - K. Suzuki, S. Takasaki

Y. Fukuta - H. Koda

S. Waku
Users Oﬃce

K. Maeda

J-PARC Annual Report 2020

Organization and Committees

63

Members of the Committees Organized for J-PARC(as of March, 2020)
1) Steering Committee (*) Chair

Junji Haba (*)

High Energy Accelerator Research Organization (KEK), Japan

Koki Uchimaru

High Energy Accelerator Research Organization (KEK), Japan

Katsuo Tokushuku

High Energy Accelerator Research Organization (KEK), Japan

Nobuhiro Kosugi

High Energy Accelerator Research Organization (KEK), Japan

Seiya Yamaguchi

High Energy Accelerator Research Organization (KEK), Japan

Yukitoshi Miura (*)

Japan Atomic Energy Agency (JAEA), Japan

Kenji Sudo

Japan Atomic Energy Agency (JAEA), Japan

Masayasu Takeda

Japan Atomic Energy Agency (JAEA), Japan

Toshiyuki Momma

Japan Atomic Energy Agency (JAEA), Japan

Hiroyuki Oigawa

Japan Atomic Energy Agency (JAEA), Japan

Naohito Saito

J-PARC Center, Japan

2) International Advisory Committee

(*) ChairJean-Michel Poutissou (*)

TRIUMF, Canada

Thomas Prokscha

Paul Scherrer Institute (PSI), Switzerland

Jun Sugiyama

Comprehensive Research Organization for Science and Society (CROSS), Japan

Jie Wei

Michigan State University, USA

Roland Garoby

European Spallation Source (ERIC), Sweden *Retired

Eckhard Elsen

European Organization for Nuclear Research (CERN), Switzerland

Patricia McBride

Fermi National Accelerator Laboratory (FNAL), USA

Robert Tribble

Brookhaven National Laboratory (BNL), USA

Donald F. Geesaman

Argonne National Laboratory, USA

Paolo Giubellino

GSI Helmholtzzentrum für Schwerionenforschung, Germany

Hamid Aït Abderrahim

SCK • CEN, Belgium

Akira Hasegawa

Tohoku University, Japan

Paul Langan

Oak Ridge National Laboratory (ORNL), USA

Hidetoshi Fukuyama

Tokyo University of Science, JapanDan Alan Neumann

National Institute of Standards and Technology (NIST), USA

Andrew Dawson Taylor

Science and Technology Facilities Council (STFC), UK

Helmut Schober

Institut Laue–Langevin, FranceOrganization and Committees

J-PARC Annual Report 2020

643) User Consultative Committee for J-PARC
Tsuyoshi Nakaya

Kyoto University, Japan

Taku Yamanaka

Osaka University, Japan

Toshinori Mori

University of Tokyo, Japan

Takashi Kobayashi

High Energy Accelerator Research Organization (KEK), Japan

Hirokazu Tamura

Tohoku University, Japan

Tomofumi Nagae (*)

Kyoto University, Japan

Hiroyuki Noumi

Osaka University, Japan

Shinya Sawada

High Energy Accelerator Research Organization (KEK), Japan

Fuminori Sakuma

RIKEN, Japan

Masaki Fujita

Tohoku University, Japan

Naoya Torikai

Mie University, Japan

Osamu Yamamuro

University of Tokyo, Japan

Yasushi Idemoto

Tokyo University of Science, Japan

Kazuhisa Kakurai

Comprehensive Research Organization for Science and Society (CROSS), Japan

Toshiya Otomo

High Energy Accelerator Research Organization (KEK), Japan

Jun Akimitsu

Okayama University/Hiroshima University, Japan

Tadashi Adachi

Sophia University, Japan

Koichiro Shimomura

High Energy Accelerator Research Organization (KEK), JapanJun Sugiyama

Comprehensive Research Organization for Science and Society (CROSS), Japan

Hiroyuki Kishimoto

Sumitomo Rubber Industries, Ltd. Japan

Hideto Imai

Nissan Analysis and Research Center, Japan

Masahiro Hino

Kyoto University, Japan

Hironori Kodama

Ibaraki Prefecture, Japan

Satoru Yamashita

University of Tokyo, Japan

Cheol-Ho Pyeon

Kyoto University, Japan

Kazufumi Tsujimoto

Japan Atomic Energy Agency (JAEA), Japan

4) Accelerator Technical Advisory Committee

(*) Chair(*) Chair

Wolfram Fischer

Brookhaven National Laboratory (BNL), USA

Mats Lindroos

European Spallation Source, Sweden

John Thomason

Science and Technology Facilities Council (STFC), UK

Sheng Wang

Institute of High Energy Physics (IHEP), China

Toshiyuki Shirai

National Institutes for Quantum and Radiological Science and Technology (QST),Japan

Alexander V Aleksandrov

Oak Ridge National Laboratory (ORNL), USA

Jie Wei (*)

Michigan State Univ., USA

Robert Zwaska

Fermi National Accelerator Laboratory (FNAL), USA

Simone Gilardoni

European Organization for Nuclear Research (CERN), Switzerland

J-PARC Annual Report 2020

Organization and Committees

655) Neutron Advisory Committee

(*) Chair

Robert McGreevy (*)

Science and Technology Facilities Council (STFC), UK

Bertrand Blau

Paul Scherrer Institut (PSI), Switzerland

Michael Dayton

Oak Ridge National Laboratory (ORNL), USA

Yoshiaki Kiyanagi

Nagoya University, Japan

Christiane Alba-Simionesco

Laboratoire Leon Brilloin (LLB), France

Jamie Schulz

Australian Nuclear Science and Technology Organization(ANSTO), Australia

Andreas Schreyer

European Spallation Source, Sweden

Sung-Min Choi

Korea Advanced Institute of Science and Technology, Korea

Yoshie Otake

RIKEN, Japan

Masaaki Sugiyama

Kyoto University, Japan

Christian Rüegg

Paul Scherrer Institute (PSI), Switzerland

6) Muon Advisory Committee

(*) Chair

Martin Månsson

KTH Royal Institute of Technology, Sweden

Thomas Prokscha (*)

Paul Scherrer Institut (PSI), Switzerland

Andrew MacFarlane

University of British Columbia, Canada

Klaus Kirch

Paul Scherrer Institut (PSI), Switzerland

Kenya Kubo

International Chiristian University, Japan

Tadayuki Takahashi

University of Tokyo, Japan

Takashi Nakano

Osaka University, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

7) Radiation Safety Committee

(*) Chair

Yoshitomo Uwamino (*)

Japan Radioisotope Association, Japan

Yoshihiro Asano

High Energy Accelerator Research Organization (KEK), Japan

Hiroshi Watabe

Tohoku University, Japan

Takeshi Iimoto

University of Tokyo, Japan

Takeshi Murakami

National Institutes for Quantum and Radiological Science and Technology (QST), Japan

Hitoshi Kobayashi

High Energy Accelerator Research Organization (KEK), Japan

Yoshihito Namito

High Energy Accelerator Research Organization (KEK), Japan

Shinichi Sasaki

High Energy Accelerator Research Organization (KEK), Japan

Hiroyuki Oigawa

Japan Atomic Energy Agency (JAEA), Japan

Takumi Nemoto

Japan Atomic Energy Agency (JAEA), Japan

Nobuyuki Kinouchi

Japan Atomic Energy Agency (JAEA), Japan

Organization and Committees

J-PARC Annual Report 2020

668) Radiation Safety Review Committee

(*) Chair

Tetsuro Ishii (*)

Japan Atomic Energy Agency (JAEA), Japan

Yukihiro Miyamoto

Japan Atomic Energy Agency (JAEA), Japan

Masaharu Numajiri

High Energy Accelerator Researchi Organization (KEK), Japan

Hidetoshi Kikunaga

Tohoku University, Japan

Hiroshi Yashima

Kyoto Univaersity, Japan

Kanenobu Tanaka

Institute of Physical and Chemical Research (RIKEN), Japan

Nobuyuki Chiga

National Institute for Quantum and Radiological Science and Technoloty (QST), Japan

Toshiro Itoga

Japan Synchrotron Radiation Research Institute (JASRI), Japan

Koji Kiriyama

Comprehensive Reserch Organization for Science and Society (CROSS), Japan

Akira Hirose

Japan Atomic Energy Agency (JAEA), Japan

Makoto Kobayashi

Japan Atomic Energy Agency (JAEA), Japan

Nobukazu Toge

High Energy Accelerator Researchi Organization (KEK), Japan

Kazuyoshi MasumotoHigh Energy Accelerator Researchi Organization (KEK), Japan

Michikazu Kinsho

Japan Atomic Energy Agency (JAEA), Japan

Yoshiaki Fujii

High Energy Accelerator Researchi Organization (KEK), Japan

Takeshi Komatsubara

High Energy Accelerator Researchi Organization (KEK), Japan

Kazuya Aizawa

Japan Atomic Energy Agency (JAEA), Japan

9) MLF Advisory Board(*) Chair

Takamitsu Kohzuma

Ibaraki University, Japan

Takahisa Arima

University of Tokyo, Japan

Taku Sato

Tohoku University, Japan

Yoji Koike

Tohoku University, Japan

Masaaki Sugiyama (*)

Kyoto University, Japan

Yoshiharu Sakurai

Japan Synchrotron Radiation Research Institute(JASRI), Japan

Jun Takahara

Kyusyu University, Japan

Takashi Kamiyama

Hokkaido University, Japan

Toshio Yamaguchi

Fukuoka University, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

Kenya Kubo

International Christian University, Japan

Toshiya Otomo

High Energy Accelerator Research Organization (KEK), Japan

Hideki Seto

High Energy Accelerator Research Organization (KEK), Japan

Takashi Kamiyama

High Energy Accelerator Research Organization (KEK), Japan

Shinichi Itoh

High Energy Accelerator Research Organization (KEK), Japan

Koichiro Shimomura

High Energy Accelerator Research Organization (KEK), Japan

Ryosuke KadonoHigh Energy Accelerator Research Organization (KEK), Japan

Kazuhisa Kakurai

Comprehensive Research Organization for Science and Society (CROSS), Japan

Kazuya Aizawa

Japan Atomic Energy Agency (JAEA), Japan

Masayasu Takeda

Japan Atomic Energy Agency (JAEA), Japan

Kazuhiko Soyama

Japan Atomic Energy Agency (JAEA), Japan

Kenji Nakajima

Japan Atomic Energy Agency (JAEA), Japan

Yukinobu Kawakita

Japan Atomic Energy Agency (JAEA), Japan

Jun-ichi Suzuki

Comprehensive Research Organization for Science and Society (CROSS), Japan

J-PARC Annual Report 2020

Organization and Committees

6710) Program Advisory Committee (PAC) for Nuclear and Particle Physics Experiments at the J-PARC 50Gev Proton
Synchrotron(*) Chair
Ichiro AdachiHigh Energy Accelerator Research Organization (KEK), Japan

Motoi Endo

High Energy Accelerator Research Organization (KEK), Japan

Yoshitaka Itow

Nagoya University, Japan

Takahiro Kawabata

Osaka University, Japan

Hiroaki OhnishiTohoku University, Japan

Akira Ohnishi

Kyoto University, Japan

Kohei Yorita

Waseda University, Japan

Patrick Achenbach

Mainz University, Germany

Monika Blanke

Karlsruhe Institute of Technology, Germany

Laura Fields

Fermi National Accelerator Laboratory (FNAL), USA

David Jaffe

Brookhaven National Laboratory (BNL), USA

Francois Le Diberder

The French National Institute of Nuclear and Particle Physics (IN2P3), France

Kam-Biu Luk

University of California at Berkley, USA

Anthony William Thomas

University of Adelaide, Australia

Nu Xu

Lawrence Berkeley National Laboratory, USA

Rikutaro Yoshida (*)

Argonne National Laboratory, USA

11) TEF Technical Advisory Committee

(*) ChairMarc Schyns (*)

SCK • CEN, Belgium

Michael Butzek

Forschungszentrum Jülich, Germany

Michael WohlmutherPaul Scherrer Institut (PSI), Switzerland

Yoshiaki Kiyanagi

Nagoya University, Japan

Keishi Sakamoto

National Institutes for Quantum and Radiological Science and Technology (QST), Japan

Georg Müller

Karlsruhe Institute of Technology, Germany

Masatoshi Kondo

Tokyo Institute of Technology, Japan

Main Parameters

Main Parameters

J-PARC Annual Report 2020

70
Present main parameters of Accelerator
Linac
Accelerated Particles
Negative hydrogen
Energy400 MeVPeak Current
50 mA
0.385 ms for MLF
0.50 ms for MR-FX
0.20 ms for MR-SX

Pulse Width
Repetition Rate
Freq. of RFQ, DTL, and SDTL
Freq. of ACS

25 Hz
324 MHz972 MHzRCS

Circumference
Injection Energy
Extraction Energy
Repetition Rate
RF Frequency
Harmonic Number
Number of RF cavities
Number of Bending Magnet

348.333 m
400 MeV
3 GeV
25 Hz
0.938 MHz → 1.67 MHz2
12
24
Main Ring

Circumference
Injection Energy
Extraction Energy
Repetition Rate
RF Frequency
Harmonic Number
Number of RF cavities
Number of Bending Magnet

1567.5 m
3 GeV
30 GeV~0.4 Hz1.67 MHz → 1.72 MHz
9996

Key parameters of Materials and Life Science Experimental Facility
Injection energy
3 GeV
Repetition rate
25 Hz
Neutron Source
Target material
Mercury
Number of moderators
3
Moderator material
Liquid hydrogen
Moderator temperature/pressure
20 K/1.5 MPa
Number of neutron beam extraction ports
23
Muon production target
Target material
Graphite
Number of muon beam extraction ports
4
Neutron instruments *Open for user program (general use)
21
Under commissioning/construction
0
Muon Instruments *Open for user program (general use)3
Under commissioning/construction
1/0(* As of August, 2021)

Events

EventsThe University of Toyama and the J-PARC
Center Signed a “Cooperative Agreementfor Using the Experimental Facilities of the
J-PARC Center in Promotion of Materials
and Life Sciences Research and Hydrogen
Isotopes Research”
On May 1, the University of Toyama and the JPARC Center signed a cooperative agreement. Both organizations will build and promote close relationshipto conduct research in fields, such as materials and life
science and hydrogen isotope studies.

The University of Tokyo and KEK Sign MoU
to promote the Hyper-Kamiokande Project
On May 25, the University of Tokyo and the HighEnergy Accelerator Research Organization (KEK) signed
a memorandum of understanding (MoU) regarding thepromotion of the Hyper-Kamiokande project. J-PARC
accelerators will dramatically expedite the experiment.

Events

J-PARC Annual Report 2020

72

Held 2020 General Assembly Meeting of
the MLF
On June 9, the General Assembly of the J-PARC Materials and Life Science and Life Science Experimental
Facility (MLF) was held remotely on Zoom. About 140
people participated in it, including the J-PARC Center,
Comprehensive Research Organization for Science andSociety (CROSS) Neutron Science and Technology Center, Ibaraki Prefecture and the universities in charge ofthe experimental equipment.
Group photo with participants

30th J-PARC PAC Held Online
The J-PARC Program Advisory Committee for Nuclear and Particle Physics Experiments (J-PARC PAC) was
held as an online three-day meeting starting on July 20.
The advice by the committee regarding new research
proposals and group reports will be compiled.

The Zoom meeting (PC screen view)

Arrangement on Research Cooperation
between JAEA and the Karlsruhe Instituteof Technology in the Field of ADS Development
JAEA and the Karlsruhe Institute of Technology(KIT) in Germany concluded the arrangement on the
research cooperation in the field of Accelerator Driven
nuclear transmutation System (ADS) development onJune 18. Both organizations will exchange informationin the area of the lead-Bismuth technology.

Tokai Village, KEK Sign “Agreement on Facility Use in Event of Disaster”
On August 4, the Inter-University Research InstituteCorporation High Energy Accelerator Research Organization (KEK) and Tokai Village have signed “Agreement
on Facility Use in the Event of a Disaster”.
It aims to make J-PARC users’ accommodations
available as evacuation shelters upon request of theTokai Village for cooperation in a disaster. The J-PARC
Center Director Naohito Saito, Deputy Director Tadashi
Koseki, Tokai Village Mayor Osamu Yamada and KEK Director General Masanori Yamauchi attended the signing ceremony.

Toyota Group and J-PARC Collaborative
Special Lecture Held Online
J-PARC and Toyota Group have advanced comprehensive collaborative research, which uses neutrons at
J-PARC as a part of the development of hydrogen energy related to taking measures against global warming.
On June 30, the J-PARC Center held an online lecture
event for collaboration. Participants exchanged information on the FC technology.
From the left, Deputy Director T. Koseki, Director N. Saito, Village Mayor O. Yamada, Associate Village Mayor H. Hagitani

J-PARC Annual Report 2020

Events73“Safety Day”
The J-PARC Center established May 23 as a “Safety
Day” after a radioactive material leak accident in 2013.
Due to the spread of the novel coronavirus, the annual
event was held on September 9.
The J-PARC Director Naohito Saito gave awards
for six good practices on safety. The category is divided into four fields of “The most Frequent Good Practices Award”, “Safety Consideration Award”, “Creativity
Award”, and “Sanitation Consideration Award”.
After the ceremony, there was a lecture on safe
behavior, and the event was closed with the remarksof the Deputy Director of Safety of the J-PARC Center,
Tetsuro Ishii.

celerator Section VII. All of them are specialists on muon
research. Eight elementary school pupils attended theclass and experimented with the movement of thespinning axis of a top.

Why doesn’t a gyroscope fall off the string?

J-PARC Virtual Open House 2020/Live
Streamed J-PARC Facilities

Mr. D. Yamazaki of the Neutron Instrumentation Section receiving a commendation (right)

The J-PARC Center held the annual open house
online this year. The special website was activated on
October 7. On the 10, there was a live-streamed event
on YouTube.
In the opening session, the Tokai Village Mayor
Osamu Yamada and the J-PARC Center Director Naohito
Saito discussed the relationship between the villageth

6 J-PARC Media Meeting Held Online
The 6th J-PARC Media Meeting was held on September 30 by videoconference. Nine people from sevencompanies participated. Neutron Science Section’s Takenao Shinohara, who is in charge of the neutron imaging system RADEN, gave examples of non-destructive
observation. Other discussed topics were the plan of
the Muon g-2/EDM experiment, the ongoing experiment at the US Fermilab, and the visualization of waterin a fuel cell using neutrons.

Quiz show hosted by Imozo and staffs from Tokai Village office

J-PARC Science Class “Can World’s Smallest
Top Explain Nobel Prize-class Discovery?!Accelerator Research to Elucidate Small
World Using Large Device-”
The J-PARC Center organized a science experimentclass at the Hitachi Civic Center Science Museum on
October 4. The instructors were Dr. Tsutomu Mibe of
Hadron Section, Deputy Director of the MLF Division
Dr. Koichiro Shimomura, and Dr. Masashi Otani of Ac-

Live streaming at MLF

Events

J-PARC Annual Report 202074
and the center. It was followed by talks and facility introductions by researchers. They answered the viewers’
questions.
This time, viewers were able to observe the insideof some facilities which are not shown in normal situations.

2020 J-PARC Emergency Drill on October
21 at the Hadron Experimental Facility
On October 21, the J-PARC Center conducted theemergency drill of JFY2020 at the Hadron Experimental
Facility. The assumed situation was a large-dose exposure during a beam operation with workers in an experimental area.
A variety of trainings were done regarding initial response, evaluation of exposure level, communications
between the incident site and the command office andthe NSRI (Nuclear Science Research Institute, in which
J-PARC locates).

JRR-3 in order to introduce the analytical techniqueusing neutron beam. Mitsutaka Nakamura, Sub Leaderof the Neutron Science Section of MLF explained therecent results.

J-PARC Hello Science at Tokai Village Children’s Science ClubA three-day event of the Tokai Village Children’s Science Club was held in November. The instructors were
Dr. Satoshi Mihara of the Particle and Nuclear Physics Division, Dr. Yasuyuki Sugiyama and Dr. Tomohiro
Takayanagi of the Accelerator Division.
The themes were on light, electricity and magneththtism. Seven 5 and 6 grade elementary pupils participated in the experiments. Some children commented
that they wanted to learn more about J-PARC because
they knew these experiments were connected with its
research work.

What will happen by layering polarizing plate, sheet with clear
adhesive tape, and more?
Activities at the On-site Command Office

J-PARC Hello Science “There is an Accelerator in the Development of Science”
Accelerators have made significant contributions
to the development of science. Dr. Tatsunobu Shibataof the Accelerator Division talked about the role of accelerators at science talk event Hello Science on October 30. He explained that the ones at J-PARC succeededin finding new particles and J-PARC can produce proton
beams with the world’s highest power level, which areessential for use in secondary particles research.

Paper clip motor made by a pupil

Participation at JASIS 2020 Exhibition

J-PARC Hello Science at Tama Rokuto Science Center “Let’s Make a Top That Leans
While Spinning! -The World of Accelerator
Research Seem from Top’s Rotation-“

JASIS (Japan Analytical & Scientific Instruments
Show) is one of the largest scientific instrument exhibitions in Asia. J-PARC exhibited in collaboration withThe J-PARC Center introduced the world of its
advanced research through craft-making and experiments at Tama Rokuto Science Center on November 29.

J-PARC Annual Report 2020

Events75
Two researchers and two public relations staffs attended the event. Dr. Masashi Otani of the Accelerator
Division and Dr. Koichiro Shimomura, Deputy Head of
the Material and Life Science Division and Public Relations Section Leader Minako Abe and science staff Naoko Inoue gave instructions to the participants.
They learned about the spin theory of elementary
particles by electric current and magnet and also by
making tops.

and the organizer changed its style and held the festival
online by collecting links of YouTube videos. The J-PARC
Center offered two videos in December. One was about
precession made by graduate students engaged in experiments at J-PARC. The other was about pendulum
bell made by the Public Relations Section.

Let’s make a pendulum bell

Participant observing magnetic field created by electric current (magnetic lines of force)

J-PARC Hello Science “Looking into Lithium-Ion Battery Using J-PARC NegativeMuon”
At J-PARC Hello Science on December 25, Dr. Izumi
Umegaki of Toyota Central R & D Labs., Inc. gave a lecture on lithium-ion battery research using a high-intensity negative muon beam in MLF. She showed that the
research would further improve the safety of lithiumion batteries, which are used in our everyday life, suchas smartphones and automobiles and contribute to thedevelopment of eco-friendly reusable batteries.

J-PARC Center’s Videos on the Official YouTube Channel of the Youngster’s Science
Festival in Hitachi
The 20th Youngster’s Science Festival in Hitachi wascanceled due to the spread of coronavirus infections

J-PARC Advisory Committees Held Online
From January 22 to February 22, the J-PARC Center
held four advisory committees online.
The committees were Transmutation Experimental
Facility (T-TAC), Accelerator Facility (A-TAC), Muon Experimental Facility (MAC), and Neutron Experimental
Facility (NAC). The purpose was to receive advice andsuggestions from experts in and out of Japan. Theirsummaries will be reported, and the J-PARC International Advisory Committee (IAC) will discuss the contents in early March.

st

The 31 J-PARC PAC Held Remotelyst

The 31 Program Advisory Committee for Nuclear
and Particle Physics Experiment at the J-PARC (PAC) was
held on January 20-22. J-PARC holds PAC twice a year
and this was the second time in JFY2020. There were
presentations of one new proposal and two that havebeen deferred in the last PAC meeting in July. The presentations were followed by eight reports on the progress and future plans.

The 3 rd “FC-Cubic Open Symposium”
Streamed on YouTube

Let’s learn about precession by making a top

FC-Cubic, a technology research association consisting of 20 companies, has been conducting research
for fuel cells with an aim to realize a hydrogen-based society. On February 2, under the co-sponsorship of NEDO(New Energy and Industrial Technology Development
Organization), the FC-Cubic Open Symposium was held

Events

J-PARC Annual Report 202076
online from the Tokyo International Exchange Center.
J-PARC participated in it, because the main topic of this
symposium was J-PARC and neutron. We also offered afacility tour by video. The total number of the symposium participants was over 1,800.

J-PARC Hello Science “Emergence of a New
Type of Neutrino?!”: Data Acquisition for
the JSNS2 Experiment Begins at J-PARC
An experiment called JSNS2, which is searching for
a new type of neutrino, “sterile neutrino”, was started at
J-PARC. Dr. Takasumi Maruyama, who is responsible forit gave a talk at Hello Science on February 26. He explained that its existence challenges the validity of the“Standard Model”, which is accepted broadly in particle
physics. For that reason, there were many questions
among the participants.

on the current status of the MLF. After that, facility staffs
delivered talks on the medium/long-term plans. Manyrequests were made by the participants under the COVID-19 crisis.

Visitors
Naokazu Takemoto, Minister of State for Special Missions, Cabinet Office (September 2)
Hiroyuki Ohta, President of Ibaraki University (September 16)
Hidehiro Mitsuya, Parliamentary Secretary of MEXT (October 20)
Takashi Shimazu, Representative of Toyota Central R&D
Labs., Inc. (November 4)
Susumu Kajiwara, Deputy Minister’s Secretariat (November 27)
Hinako Takahashi, Deputy Minister of MEXT (December
16)

At the event site

There were 362 visitors to J-PARC for theperiod from April 2020, to the end of
March 2021.

J-PARC International Advisory Committee
The meeting of the International Advisory Committee (IAC) was held on March 4 and 5. It was the summary of the four meetings of T-TAC, A-TAC, MAC, and
NAC in January and February. On the second day, IAC
announced its advice presented by the Chair of thecommittee, Jean-Michel Poutissou of the TRIUMF Research Center in Canada.

Quantum Beam Science Festa FY2020
The Quantum Beam Science Festa was held online
on March 9-11. 614 people attended, mostly MLF and
KEK Photon Factory (PF) users. On the first day, the MLF
Symposium kicked off with an opening message by Kazuhiko Soyama, Senior Principal Research at the J-PARC
Center. He announced that the operation of JRR-3 wasresumed in February. Then Toshiya Otomo, Head of theMaterials and Life Science Division presented a report

Junior-high/High school
students, teachers
7%

VIP, lawmakers
5%ln-house
11%

Public Officers
12%

Business
20%

University students,
experts37%

Local
residents
6%

Media
2%

Publications

Publications

J-PARC Annual Report 202078

Publications in Periodical Journals
A-001
A. S. Tremsin, et al.
In-situ observation and analysis of solidstate diffusion and liquid migration in a
crystal growth system: A segregation-driven
diffusion couple
Acta Mater., 186 434-442 (2020)

A-010
M. Tanaka, et al.
Structure determination of the human
TRPV1 ankyrin-repeat domain under
nonreducing conditions
Acta Crystallogr. Sect. F Struct. Biol. Cryst.
Commun., F76 130-137 (2020)

A-002
M. Morgano, et al.
Investigation of the effect of Laser ShockPeening in Additively Manufactured samples
through Bragg Edge Neutron Imaging
Addit. Manuf., 34 101201 (2020)

A-011
Y. Wang, et al.
Real time observation of martensite
transformation for a 0.4 C low alloyed steel
by neutron diffraction
Acta Mater., 184 30-40 (2020)

A-003
H. Iwamoto
Generation of nuclear data using Gaussian
process regression
J. Nucl. Sci. Technol., 57, pp. 932-938

A-012
Y. Wang, et al.
Continuous and discontinuous yielding
behaviors in ferrite-cementite steels
Acta Mater., 196 565-575 (2020)

A-004
T. Hirata, et al.
A Facile Surface Functionalization Method
for Polymers Using a Non-solvent
ACS Appl. Bio Mater., 3 2170-2176 (2020)

A-013
S. Harjo, et al.
Neutron diffraction monitoring of ductile
cast iron under cyclic tension–compression
Acta Mater., 196 584-594 (2020)

A-005
J. H. Hong, et al.
Design of a Bio-inert Interface Using an
Amphiphilic Block Copolymer Containing a
Bottlebrush Unit of Oligo(oxazoline)
ACS Appl. Bio Mater., 3 7363–7368 (2020)

A-014
D. Fukui, et al.
Internal residual stress originated from Bainstrain and its effect on hardness in Fe–Ni
martensite
Acta Mater., 196 660-668 (2020)

A-006
K. Mori, et al.
Experimental Visualization of Interstitialcy
Diffusion Pathways in Fast-Fluoride-IonConducting Solid Electrolyte Ba0.6La0.4F2.4
ACS Appl. Energy Mater., 3 2873 (2020)

A-015
T. N. Lam, et al.
Enhancement of fatigue resistance byoverload-induced deformation twinning in a
CoCrFeMnNi high-entropy alloy
Addit. Manuf., 34 101201 (2020)

A-007
K. Shiino, et al.
Structural investigation of sulfonatedpolyphenylene ionomers for the designof better performing proton-conductive
membranes
ACS Appl. Polym. Mater., 2 5558-5565 (2020)

A-016
L. Kong, et al.
Suppressed Lattice Disorder for Large
Emission Enhancement and Structural
Robustness in Hybrid Lead Iodide Perovskite
Discovered by High-pressure Isotope EffectAdv. Funct. Mater., 31 2009131 (2020)

A-008
S. Utsumi, et al.
Flux Growth and Magnetic Properties ofHelimagnetic Hexagonal Ferrite Ba(Fe1–xScx)12O19 Single Crystals
ACS Omega, 5 24890-24897 (2020)

A-017
K. Hayashi, et al.
Preparation, thermoelectric properties, andcrystal structure of boron-doped Mg2Si
single crystals
AIP Adv., 10 35115 (2020)

A-009
T. Sato, et al.
Crystal Structural Investigations for
Understanding Hydrogen Storage Properties
of YMgNi4-Based Alloys
ACS Omega, 5 31192 (2020)

A-018
Y. Umegaki, et al.
Nondestructive High-Sensitivity Detectionsof Metallic Lithium Deposited on a Battery
Anode Using Muonic X-rays
Anal. Chem., 92 8194 (2020)

A-019
T. Takami, et al.
A new Bi0.7Fe1.3O1.5F1.7 phase: Crystal
structure, magnetic properties, and cathode
performance in fluoride-ion batteries
APL Mater., 8 051103 (2020)
A-020
H. Seto, T. Yamada
Quasi-elastic neutron scattering study ofthe effects of metal cations on the hydrationwater between phospholipid bilayers
Appl. Phys. Lett., 116 133701 (2020)
A-021
H. K. Cho, S. Park
Magnetic structure of undistorted hexagonal
ferrites, Lu0.2In0.8FeO3
Appl. Phys. Lett., 116 202902 (2020)
A-022
H. Yamamoto, et al.
Reversible thermally controlled spontaneous
magnetization switching in perovskite-type
manganite
Appl. Phys. Lett., 117 112404 (2020)
A-023
J. Kitanishi, et al.
Identification and Characterization of a
Redox Sensor Phosphodiesterase from
Ferrovum sp. PN-J185 Containing Bacterial
Hemerythrin and HD-GYP Domains
Biochemistry, 59 983-991 (2020)
A-024
H. Kawaura, et al.
Operando Time-slicing Neutron
Reflectometry Measurements of Solid
Electrolyte Interphase Formation on
Amorphous Carbon Surfaces of a Li-ion
Battery
Bull. Chem. Soc. Jpn., 93 854-861 (2020)
A-025
H. Uchiyama, et al.
Single-stranded β-1,3–1,6-glucan as a carrier
for improved dissolution and membrane
permeation of poorly water-solublecompounds
Carbohydr. Polym., 247 116698 (2020)
A-026
Y. Fujii, et al.
Cation- and anion-ordered rutile-type
derivative LiTeO3(OH)
Chem. Commun., 56 10042-10045 (2020)
A-027
J. Yamaura, et al.
Polar nano-region structure in oxynitride
perovskite LaTiO2N
Chem. Commun., 56 1385-1388 (2020)

J-PARC Annual Report 2020

Publications

79
A-028
H. Yamauchi, et al.
High-temperature short-range order in
Mn3RhSi
Commun. Mater., 1 43 (2020)
A-029
R. Sei, et al.
Tetragonality induced superconductivity in
anti-ThCr2Si2-type RE2O2Bi (RE = rare earth)with Bi square nets
Dalton Trans., 49 3321-3325 (2020)
A-030
R. Kasai, et al.
Effect of Separator and Anode on
Electrochemical Characteristics andCrystal Structure of Lithium-ion
Battery Cathode Material 0.4Li2MnO30.6LiMn1/3Ni1/3Co1/3O2
Electrochemistry, 89 148-156 (2020)
A-031
T. Nakaya, K. Nishikawa
Long baseline neutrino oscillation
experiments with accelerators in Japan
European Physical Journal C 80(2020) 334
A-032
T. Yamada, H. Seto,
Quasi-Elastic Neutron Scattering Studies on
Hydration Water in Phospholipid Membranes
Front. Chem., 8 8 (2020)
A-033
J. Pallbo, et al.
NACore amyloid formation in the presenceof phospholipids
Front. Physiol., 11 592117 (2020)
A-034
K. Komatsu, et al.
Developments of nano-polycrystalline
diamond anvil cells for neutron diffraction
experiments
High Press. Res., 40 184-193 (2020)
A-035
T. Hattori, et al.
Practical effects of pressure-transmitting
media on neutron diffraction experiments
using Paris-Edinburgh presses
High Press. Res., 40 325-338 (2020)
A-036
M. Nitta, et al.
High-Brightness Red-Emitting Phosphor
La3(Si,Al)6(O,N)11:Ce3+ for Next-Generation
Solid-State Light Sources
High-Brightness Red-Emitting Phosphor
La3(Si,Al)6(O,N)11:Ce3+ for Next-Generation
Solid-State Light Sources
A-037
M. Iio, et al.
Research and Development of Future
Radiation-Resistant Superconducting

Magnets With Mineral Insulated REBCO Coils
IEEE Trans. Appl. Supercond., 30 (2020),
4600505

Titanium Hydride Complex BaCa2Ti2H14
with a 9-Fold Coordination
Inorg. Chem., 59 4228-4233 (2020)

A-038
W. Liao, et al.
Impact of the Angle of Incidence on
Negative Muon-induced SEU Cross Sectionsof 65-nm Bulk and FDSOI SRAMs
IEEE Trans. Nucl. Sci., 67 1566-1572 (2020)

A-047
Y. Matsumoto, et al.
High-pressure Synthesis of Ba2CoO2Ag2Te2
with Extended CoO2 Planes
Inorg. Chem., 59 8121–8126 (2020)

A-039
J. Kuroda, et al.
Measurement of Single-Event Upsets in 65nm SRAMs Under Irradiation of Spallation
Neutrons at J-PARC MLF
IEEE Trans. Nucl. Sci., 67 1599-1605 (2020)

A-048
H. Sato, et al.
Simultaneous Broadening Analysisof Multiple Bragg Edges Observed by
Wavelength-resolved Neutron Transmission
Imaging of Deformed Low-carbon Ferritic
Steel
ISIJ International, 60 1254-1263 (2020)

A-040
N. Amemiya, et al.
AC Loss and Shielding-Current-Induced
Field in a Coated-Conductor Test Magnet for
Accelerator Applications under Repeated
Excitations
IEEE Transactions on Applied
Superconductivity 30 (2020) 4004105

A-049
N. Tsuchida, et al.
Analysis of Tensile Deformation Behavior byin situ Neutron Diffraction Experiments of 1
GPa-grade TRIP Steels with High Elongation
ISIJ International, 60 1349-1357 (2020)

A-041
T. Obana, T. Ogitsu
Design of Lightweight Superconducting
Magnets for a Rotating Gantry With Active
ShieldingIEEE Transactions on Applied
Superconductivity 30 (2020) 4400305
A-042
K. TANAKA, et al.
New Types of Organic Resins for Insulation ofWarm Magnets
IEEE Transactions on Applied
Superconductivity 30 (2020) 7700105
A-043
T. Takayanagi, et al.
Comparative studies of three-dimensional
analysis and measurement for establishingpulse electromagnet designIEEE Transactions on Applied
Superconductivity, 30(4)(2020), p.4901605_1 4901605_5
A-044
T. Kishishita, et al.
SliT: A Strip-Sensor Readout Chip With
Subnanosecond Time Walk for the J-PARC
Muon g - 2/EDM ExperimentIEEE Transactions on Nuclear Science 67 (2020)
2089
A-045
T. Matsubara, et al.
Cation distributions and magnetic propertiesof ferrispinel MgFeMnO4
Inorg. Chem., 59 17970-17980 (2020)
A-046
T. Yajima, et al.

A-050
Y. Hosoya, et al.
Mechanism of Improved Ductility of 1500
MPa-class Ultra-high Strength Cold-rolled
Steel Sheet Produced by Rolling andPartitioning Method
ISIJ International, 60 2097 (2020)
A-051
T. Wakisaka, et al.
Rational Synthesis for a Noble Metal Carbide
J. Am. Chem. Soc., 142 1247 (2020)
A-052
X. Zhang, et al.
Distance-Selected Topochemical
Dehydro-Diels-Alder Reaction of
1,4-Diphenylbutadiyne toward Crystalline
Graphitic Nanoribbons
J. Am. Chem. Soc., 142 17662-17669 (2020)
A-053
N. L. Yamada, et al.
Application of Precise Neutron Focusing
Mirror for Neutron Reflectometry - Latest
Results and Future Prospects
J. Appl. Crystallogr., 53 1462-1470 (2020)
A-054
Y. Akahama, et al.
Structure refinement of black phosphorus
under high pressure
J. Chem. Phys., 153 014704 (2020)
A-055
J. Matsuno, et al.
Synthesis and characterization of
nanoemulsion-mediated core crosslinked
nanoparticles, and in vivo pharmacokinetics
depending on the structural characteristics
J. Control. Release, 324 405 (2020)

Publications

J-PARC Annual Report 2020

80
A-056
M. Aggarwal, et al.
Energy Resolved Neutron Imaging for Strain
Reconstruction Using the Finite Element
MethodJ. Imaging, 6 13 (2020)
A-057
T. Aoyagi, et al.
Performance evaluation of a silicon strip
detector for positrons/electrons from apulsed a muon beam
J. Instrum., 15 P04027 (2020)
A-058
S. Okada, et al.
X-ray Spectroscopy of Muonic Atoms
Isolated in Vacuum with Transition Edge
Sensors
J. Low. Temp. Phys., 200 445-451 (2020)
A-059
T. E. Ashton, et al.
Multiple diffusion pathways in
LixNi0.77Co0.14Al0.09O2 (NCA) Li-ion
battery cathodes
J. Mater. Chem. A, 8 11545-11552 (2020)
A-060
H. Abe, et al.
CO2 capture and surface structures of ionicliquid-propanol solutions
J. Mol. Liq., 301 112445 (2020)
A-061
K. Sakai, et al.
Conceptual design of an abnormality sign
determination system for the general control
system of the Materials and Life Science
Experimental Facility at J-PARC
J. Neutron Res., 22 337-343 (2020)
A-062
M. Kajimoto, et al.
Energy resolution and neutron flux of the
4SEASONS spectrometer revisited
J. Neutron Res., 22 99-107 (2020)
A-063
Y. Iwamoto, et al.
Estimation of reliable displacements-peratom based on athermal-recombinationcorrected model in radiation environments
at nuclear fission, fusion, and accelerator
facilities
J. Nucl. Mat. 538, pp. 152261
A-064
T. Ishida, et al.
Tensile behavior of dual-phase titanium
alloys under high-intensity proton beam
exposure: Radiation-induced omega phasetransformation in Ti-6Al-4V
J. Nucl. Mater., 541 152413 (2020)
A-065
H. Matsuda, et al.

Measurement of Displacement CrossSections of Copper and Iron for Proton withKinetic Energies in the Range 0.4 - 3 GeV
J. Nucl. Sci. Technol., 57, pp. 1141-1151
A-066
H. Takei, et al.
Low-power proton beam extraction by thebright continuous laser using the 3-MeV
negativehydrogen linac in Japan Proton
Accelerator Research Complex
J. Nucl. Sci. Technol., 58, pp. 580-603
A-067
H. Iwamoto, et al.
Estimation of uncertainty in lead spallation
particle multiplicity and its propagation to aneutron energy spectrum
J. Nucl.Sci. Technol., 57, pp. 276 - 290
A-068
Y. Kameda, et al.
Solvation Structure of Li+ in Concentrated
Acetonitrile and N,N-Dimethylformamide
Solutions Studied by Neutron Diffraction
with 6Li/7Li Isotopic Substitution Methods
J. Phys. Chem. B, 124 10456 (2020)
A-069
K. Yoshimoto, et al.
Principal Vibration Modes of the La2O3−
Ga2O3 Binary Glass Originated from Diverse
Coordination Environments of Oxygen
Atoms
J. Phys. Chem. B, 124 5056-5066 (2020)
A-070
Z. Liu, et al.
Heterogeneity of Water Molecules on theFree Surface of Thin Reduced Graphene
Oxide Sheets
J. Phys. Chem. C Nanomater. Interfaces, 124
11064-11074 (2020)
A-071
Y. Zhou, et al.
Dihydrogen Bonds in Aqueous NaBD4Solution by Neutron and X-Ray Diffraction
J. Phys. Chem. Lett., 11 1622 (2020)
A-072
M. A. González, et al.
Nanoscale Relaxation in “Water-in-Salt” and“Water-in-Bisalt” Electrolytes
J. Phys. Chem. Lett., 11 7279 (2020)
A-073
T. Hiroto, et al.
Noncoplanar ferrimagnetism and local
crystalline-electric-field anisotropy in thequasicrystal approximant Au70Si17Tb13
J. Phys. Condens. Matter, 32 415802 (2020)
A-074
M. Abe, et al.
Development of a µ-PIC with glass substrate
aiming at high gas gain

J. Phys. Conf. Ser., 1498 012002 (2020)
A-075
M. Komabuchi, et al.
Crystal Structure and Cation Distribution of
the X-type Hexaferrite Sr2Co2Fe28O46
J. Physical Soc. Japan, 89 034601 (2020)
A-076
M. Kofu, O. Yamamuro
Dynamics of Atomic Hydrogen in Palladium
Probed by Neutron Spectroscopy
J. Physical Soc. Japan, 89 051002 (2020)
A-077
K. Iida, et al.
Horizontal line nodes in Sr2RuO4 proved byspin resonance
J. Physical Soc. Japan, 89 053702 (2020)
A-078
K. Sato, et al.
Coexistence of Two Components in
Magnetic Excitations of La2-xSrxCuO4 (x =0.10 and 0.16)
J. Physical Soc. Japan, 89 114703 (2020)
A-079
S. Ikeda, et al.
Multi-Step Magnetic Transitions in EuNiIn4
J. Physical Soc. Japan, 89 14707 (2020).
A-080
K. Otomo, et al.
Structural Studies of Hydrogen Storage
Materials with Neutron Diffraction: A Review
J. Physical Soc. Japan, 89 51001 (2020)
A-081
T. U. Ito, et al.
Negatively Charged Muonium and RelatedCenters in Solids
J. Physical Soc. Japan, 89 51007 (2020)
A-082
T. Noda, et al.
Preparation, characterization, and dilute
solution properties of four‐branched cage‐
shaped poly (ethylene oxide)
J. Polym. Sci., 58 2098-2107 (2020)
A-083
R. Iizuka-Oku, W. Gui, K. Komatsu, T. Yagi, H.
Kagi,
High-pressure responses of alkali metalhydrogen carbonates, RbHCO3and CsHCO3:
Findings of new phases and uniquecompressional behavior
J. Solid State Chem., 283 121139 (2020)
A-084
J. Hendriks, et al.
Bayesian non-parametric Bragg-edge fitting
for neutron transmission strain imaging
J. Strain Anal. Eng. Des., (2020)

J-PARC Annual Report 2020

Publications

81
A-085
K. Abe, et al.
Measurement of the charged-current
electron (anti-)neutrino inclusive crosssections at the T2K off-axis near detector
ND280
Journal of High Energy Physics 10 (2020) 114

A-095
H. Matsuda, et al
Measurement of displacement crosssections of copper and iron for proton withkinetic energies in the range 0.4 -- 3 GeV
Journal of Nuclear Science and Technology 57(2020) 1141

A-086
R. Acciarri, et al.
The Liquid Argon In A Testbeam (LArIAT)
experiment
Journal of Instrumentation 15 (2020) P04026

A-096
F. Funama, et al.
Observation of TOF-MIEZE Signals with
Focusing Mirrors at BL06, MLF, J-PARC
Journal of Surface Investigation: X-ray,
Synchrotron and Neutron Techniques, 14
S50-S55 (2020)

A-087
T. Aoyagi, et al.
Performance evaluation of a silicon strip
detector for positrons/electrons from apulsed a muon beam
Journal of Instrumentation 15 (2020) P04027
A-088
A.Blondel, et al.
The SuperFGD Prototype charged particle
beam tests
Journal of Instrumentation 15 (2020) P12003
A-089
J. S. Park(*), et al.
Performance of PMTs for the JSNS2experiment
Journal of Instrumentation 15 (2020) T07003
A-090
J. S. Park(*), et al.
The JSNS2 data acquisition system
Journal of Instrumentation 15 (2020) T09002
A-091
T. Kishishita, et al.
LTARS: analog readout front-end ASIC for
versatile TPC-applications
Journal of Instrumentation 15 (2020) T09009
A-092
T. Hashimoto, et al.
Integration of a TES-based X-ray
spectrometer in a kaonic atom experiment
Journal of Low Temperature Physics 199 (2020)
1018
A-093
D. Kitahara, et al.
The location of Mn and Fe in axinite–(Fe)from Nandan, China determined byanomalous X–ray scattering (AXS)
Journal of Mineralogical and Petrological
Sciences, 115 227-235 (2020)
A-094
M. Nagashima, et al.
Crystal chemistry of Sr–rich piemontite frommanganese ore deposit of the Tone mine,
Nishisonogi Peninsula, Nagasaki, southwest
Japan
Journal of Mineralogical and Petrological
Sciences, 115 391-406 (2020)

Neutron Reflectometry under Controlled
Temperature and Humidity Conditions
Langmuir, 36 4955-4963 (2020)
A-104
T. Yoshimura, et al.
Adsorption and aggregation properties ofGemini-type amphiphilic dendrimers
Langmuir, 36 563 (2020)
A-105
K. Igata, et al.
Cationic Polymer Brush/Giant Polysaccharide
Sacran Assembly: Structure and Lubricity
Langmuir, 36 6494-6501 (2020)

A-097
K. Kataoka
Oxide single crystals with high lithium-ion
conductivity as solid electrolytes for all-solidstate lithium secondary battery applications
Journal of the Ceramic Society of Japan, 128
7-18 (2020)

A-106
S. Yada, et al.
Microstructural Characterization of Foam
Formed by a Hydroxy Group-Containing
Amino Acid Surfactant Using Small-Angle
Neutron Scattering
Langmuir, 36 7808–7813 (2020)

A-098
Z. Xu, et al.
Hydrogen states in hydrogen-passivatedsemiconducting barium disilicide measured
via muon spin rotation
Jpn. J. Appl. Phys., 59 071004 (2020)

A-107
Y. Higaki, et al.
Hydration State Variation of Polyzwitterion
Brushes through Interplay with Ions
Langmuir, 36 9015 (2020)

A-099
K. Ito, et al.
Water Distribution in Nafion Thin Films
on Hydrophilic and Hydrophobic Carbon
Substrates
Langmuir, 36 12830–12837 (2020)
A-100
T. Miyazaki, et al.
Neutron Reflectivity on the Mobile Surface
and Immobile Interfacial Layers in the
Poly(vinyl acetate) Adsorption Layer on a Si
Substrate with Deuterated Toluene VaporInduced Swelling
Langmuir, 36 15181-15188 (2020)
A-101
T. Miyazaki, et al.
Detailed Structural Study on the Poly(vinyl
alcohol) Adsorption Layers on a Si Substratewith Solvent Vapor-Induced Swelling
Langmuir, 36 3415-3424 (2020)
A-102
T. Sugahara, et al.
Structural change of α-gel (α-form hydrated
crystal) induced by temperature and shear
flow in an oleic acid-based gemini surfactant
systemLangmuir, 36 4695-4701 (2020)
A-103
T. Kimura, et al.
Sublayered Thin Films of Hydrated Anion
Exchange Ionomer for Fuel Cells Formedon SiO2 and Pt Substrates Analyzed by

A-108
C.I. Gupit, et al.
Nanostructures and viscosities of nafion
dispersions in water/ethanol from dilute toconcentrated regimes
Macromolecules, 53 1464 (2020)
A-109
Y. Oda, et al.
Dynamic Interface based on Segregationof an Amphiphilic Hyperbranched Polymer
Containing Fluoroalkyl and Oligo(ethyleneoxide) Moieties
Macromolecules, 53 2380-2387 (2020)
A-110
M. Ohira, et al.
Quantitative structure analysis of a nearideal polymer network with deuterium label
by small-angle neutron scattering
Macromolecules, 53 4047 (2020)
A-111
A. Izumi, et al.
Interfacial Cross-Link Inhomogeneity ofa Phenolic Resin on a Silica Surface As
Revealed by X-ray and Neutron Reflection
Measurements
Macromolecules, 53 4082-4089 (2020)
A-112
K. Tashiro, et al.
Introduction of Disorder in the Crystal
Structures of Atactic Poly(vinyl Alcohol)
and Its Iodine Complex To Solve a Dilemma
between X-ray and Neutron Diffraction Data
AnalysesPublications

J-PARC Annual Report 2020

82
Macromolecules, 53 6656-6671 (2020)
A-113
T. Nishimura, et al.
Determining the hydration in thehydrophobic layer of permeable polymer
vesicles by neutron scattering
Macromolecules, 53 7546 (2020)
A-114
Y. Cui, et al.
A study on the micromechanical behavior
of Ti-55531 titanium alloy with lamellar
microstructure byin-situ neutron diffraction
MATEC Web of Conferences, 321 11013 (2020)
A-115
Y. Tomota, et al.
Influence of carbon concentration andmagnetic transition on the austenite T lattice
parameter of 30Mn-C steel
Mater. Charact., 163 110243 (2020)
A-116
D. Ma, et al.
In-situ neutron diffraction investigationon the martensite transformation, texture
evolution and martensite reversion in highmanganese TRIP steel
Mater. Charact., 163 110244 (2020)
A-117
Z. Wei, et al.
Transformation textures in pure titanium:
Texture memory vs surface effect
Mater. Charact., 164 110359 (2020)
A-118
K. Itoh, et al.
Structural study of Ni67Zr33 amorphousalloy: Interatomic space analysis approach
Mater. Chem. Phys., 240 122214 (2020)
A-119
W. Woo, et al.
Comparison of dislocation density, twin
fault probability, and stacking fault energy
between CrCoNi and CrCoNiFe medium
entropy alloys deformed at 293 and 140K
Mater. Sci. Eng. A Struct. Mater., 781 139224(2020)A-120
S. Harjo, et al.
Neutron Diffraction Monitoring of As-Cast
Mg97Zn1Y2 during Compression andTensionMater. Trans., 61 828-832 (2020)
A-121
J. W. Bae, et al.
On the phase transformation and dynamic
stress–strain partitioning of ferrous mediumentropy alloy using experimentation andfinite element method
Materialia, 9 100619 (2020)

A-122
T. Kai, et al.
Feasibility Study of Two-Dimensional
Neutron-Resonance Thermometry using
Molybdenum in 316 Stainless-SteelMaterials Research Forum LLC, 15 149-153(2020)A-123
K. Oikawa, et al.
Pulsed Neutron Imaging Based
Crystallographic Structure Study of aJapanese Sword made by Sukemasa in the
Muromachi Period
Materials Research Forum LLC, 15 207-213(2020)A-124
J. D. Parker, et al.
Development of Event-Type Neutron
Imaging Detectors at the Energy-Resolved
Neutron Imaging System RADEN at J-PARC
Materials Research Proceedings, 15 102-107(2020)A-125
Y. Oba, et al.
Neutron Transmission Spectrum of Liquid
Lead Bismuth Eutectic
Materials Research Proceedings, 15 160-164(2020)A-126
H. Sato, et al.
Crystallographic Microstructure Study of aJapanese Sword made by Noritsuna in the
Muromachi Period by Pulsed Neutron BraggEdge Transmission Imaging
Materials Research Proceedings, 15 214-220(2020)A-127
Y. Matsumoto, et al.
Comparative Study of Ancient andModern Japanese Swords using Neutron
Tomography
Materials Research Proceedings, 15 221-226(2020)A-128
K. Ohmae, et al.
Crystallographic Structure Study of aJapanese Sword Masamitsu made in the1969 using Pulsed Neutron Imaging
Materials Research Proceedings, 15 227-232(2020)A-129
O. Holderer, et al.
Fuel Cell Electrode Characterization Using
Neutron Scattering
Materials, 13 1474 (2020)
A-130
T. N. Lam, et al.
Element Effects of Mn and Ge on the Tuningof Mechanical Properties of High-Entropy

Alloys
Metall. Mater. Trans. A Phys. Metall. Mater. Sci.,
51 5023-5028 (2020)
A-131
I. Tanaka, et al.
Current status and near future plan ofneutron protein crystallography at J-PARC
Methods Enzymol., 634 101-123 (2020)
A-132
M. B. Spano, et al.
Large crystal growth for neutron protein
crystallography
Methods Enzymol., 634 21-46 (2020)
A-133
S. Urakawa, et al.
X-ray and neutron study on the structure ofhydrous SiO2 glass up to 10 GPa
Minerals, 10 84 (2020)
A-134
S. Kajiyama, et al.
Shear-induced liquid-crystalline phasetransition behaviour of colloidal solutions ofhydroxyapatite nanorod composites
Nanoscale, 12 11468-11479 (2020)
A-135
K. Watanabe, et al.
Highly asymmetric lamellar nanostructuresfrom nanoparticle–linear hybrid block
copolymers
Nanoscale, 12 16526-16534 (2020)
A-136
W. Zhang, et al.
Oxide-ion conduction in the Dion–Jacobson
phase CsBi2Ti2NbO10−δ
Nat. Commun., 11 1224 (2020)
A-137
Q. Ren, et al.
Establishing the carrier scattering phase
diagram for ZrNiSn-based half-Heusler
thermoelectric materials
Nat. Commun., 11 3142 (2020)
A-138
M. Fujihala, et al.
Gapless spin liquid in a square-kagome
lattice antiferromagnet
Nat. Commun., 11 3429 (2020)
A-139
F. B. Li, et al.
Understanding colossal barocaloric effects inplastic crystals
Nat. Commun., 11 4190 (2020)
A-140
K. Komatsu, et al.
Ice Ic without stacking disorder by
evacuating hydrogen from hydrogenhydrateNat. Commun., 11 464 (2020)

J-PARC Annual Report 2020

Publications

83
A-141
T. Yamamoto, et al.
Strain-induced creation and switchingof anion vacancy layers in perovskite
oxynitrides
Nat. Commun., 11 5923 (2020)
A-142
X. Li, et al.
Ultralow Thermal Conductivity fromTransverse Acoustic Phonon Suppression in
Distorted Crystalline α-MgAgSb
Nat. Commun., 11 942 (2020)
A-143
K. Abe, et al.
Constraint on the matter-antimatter
symmetry-violating phase in neutrino
oscillations
Nature 580(2020) n339
A-144
M. L. Friend
A decade of science at J-PARC
Nature Reviews Physics 2 (2020) 2
A-145
R. Bauer, et al.
Slow compression of crystalline ice at low
temperature
Nature, 585 E10 (2020)
A-146
P. Wu, et al.
Strong lattice anharmonicity exhibitedby the high-energy optical phonons inthermoelectric material
New J. Phys., 22 083083 (2020)
A-147
P. Gwak, et al.
Slow Control and Monitoring programmingfor JSNS2
New Physics: Sae Mulli 70 (2020) 928
A-148
Z. Xu, et al.
Strong local moment antiferromagnetic spin
fluctuations in V-doped LiFeAs
NPJ Quantum Mater., 5 11 (2020)
A-149
T. Okudaira, et al.
Development and application of a 3He
neutron spin filter at J-PARC
Nucl. Instrum. Methods Phys. Res. A, 977
164301 (2020)
A-150
T. Naoe, et al.
Pressure wave induced sound measurementfor diagnosing the operation status of the
J-PARC pulsed spallation neutron source
Nucl. Instrum. Methods Phys. Res. A, 982
164566 (2020)

A-151
H. Matsuda, et al.
Measurement of thick target neutron yield at
180°for a mercury target induced by 3-GeV
protons
Nucl. Instrum. Methods Phys. Res. B 483, pp.
33–40

A-160
M. Kawano, et al.
Mixing states of imidazolium-based ionicliquid, [C4mim][TFSI], with cycloethers
studied by SANS, IR, and NMR experiments
and MD simulations
Phys. Chem. Chem. Phys., 22 5332-5346 (2020)

A-152
R. Murayama, et al.
A new cylindrical photon-veto detector for
the KL → π0νν experiment
Nucl. Instrum. Methods Phys. Res. Section A
953 (2020) 163255

A-161
Y. Higuchi, et al.
Pulsed neutron imaging for differentiation of
ice and liquid water towards fuel cell vehicle
applications
Phys. Chem. Chem. Phys., 23 1062-1071 (2020)

A-153
Y. Nakazawa, et al.
Radiation hardness study for the COMET
Phase-I electronics
Nucl. Instrum. Methods Phys. Res. Section A
955 (2020)n163247

A-162
M. Nagashima, et al.
Multi-methodical study of the Ti, Fe2+ andFe3+ distribution in chevkinite-subgroupminerals: X-ray diffraction, neutron
diffraction, 57Fe Mössbauer spectroscopy
and electron-microprobe analyses
Phys. Chem. Miner., 47 29 (2020)

A-154
T. Yamanaka, et al.
Positron tracking detector for J-PARC muong--2/EDM experiment
Nucl. Instrum. Methods Phys. Res. Section A
958 (2020) 162786
A-155
H. Nishiguchi, et al.
Construction on vacuum-compatible straw
tracker for COMET Phase-I
Nucl. Instrum. Methods Phys. Res. Section A
958 (2020) 162800
A-156
Y. Sato, et al.
Development of a front-end ASIC for siliconstrip detectors of the J-PARC muon g-2/EDM
experiment
Nucl. Instrum. Methods Phys. Res. Section A
969 (2020) 164035
A-157
K. Sato, et al.
CsI calorimeter for the J-PARC KOTO
experiment
Nucl. Instrum. Methods Phys. Res. Section A
982 (2020) 164527
A-158
A. W. Thomas, et al.
Ten Years of the Asian Nuclear Physics
Association (ANPhA) and Major Accelerator
Facilities for Nuclear Physics in the Asia
Pacific Region
Nuclear Physics News 30 (2020· 3
A-159
Y. Zhou, et al.
The Structural Elucidation of Aqueous
H3BO3 Solutions by DFT and Neutron
Scattering
Phys. Chem. Chem. Phys., 22 17160-17170(2020)A-163
H. Hotchi
Effects of the Montague resonance on theformation of the beam distribution duringmultiturn injection painting in a highintensity proton ring
Phys. Rev. Accel. Beams (Internet), 23(5),p.050401_1 - 050401_13, 2020/05
A-164
P. Saha, et al.
First measurement and online monitoringof the stripper foil thinning and pinhole
formation to achieve a longer foil lifetime inhigh-intensity accelerators
Phys. Rev. Accel. Beams (Internet), 23(8),p.082801_1 - 082801_13, 2020/08
A-165
Y. Shobuda, et al.
Titanium nitride-coated ceramic break forwall current monitors with an improved
broadband frequency response
Phys. Rev. Accel. Beams (Internet), 23(9),p.092801_1 - 092801_18, 2020/09
A-166
S. Meigo, et al.
Two-parameter model for optimizing target
beam distribution with an octupole magnet
Phys. Rev. Accel. Beams 23, 062802
A-167
T. Morishita, et al.
Electromagnetic design and tuning of the
four-vane radio frequency quadrupole withnonuniform intervane voltage profile
Phys. Rev. Accel. Beams 23, 111003-1 – 1110039 (2020)
A-168
T.Yasui, et al.
Transverse emittance growth caused byPublications

J-PARC Annual Report 202084
space-charge-induced resonancePhys. Rev. Accel. Beams 23, 61001- (2020)
A-169
T. Oda, et al.
Tuning Neutron Resonance Spin-Echo
Spectrometers with Pulsed Beams
Phys. Rev. Appl., 14 054032 (2020)
A-170
E. Fogh, et al.
Magnetic structures and quadraticmagnetoelectric effect in LiNiPO4 beyond
30 T
Phys. Rev. B, 101 024403 (2020).
A-171
T. Uchino, et al.
Proximity coupling of superconducting
nanograins with fractal distributions
Phys. Rev. B, 101 035146 (2020)
A-172
T. Sato, et al.
Magnetic phase diagram enrichedby chemical substitution in anoncentrosymmetric helimagnet
Phys. Rev. B, 101 054414 (2020)
A-173
S. Klotz, et al.
Crystal structure and magnetism of MnO
under pressure
Phys. Rev. B, 101 064105 (2020)
A-174
K. H. Lee, et al.
Stabilization of orthorhombic distortions in
Cu- and Co-doped ferrimagnetic Mn3O4
Phys. Rev. B, 101 085126 (2020)

A-179
H. Masuda, et al.
Field-induced spin reorientation in theantiferromagnetic Dirac material EuMnBi2
revealed by neutron and resonant x-ray
diffraction
Phys. Rev. B, 101 174411 (2020)
A-180
N. Abe, et al.
Magnetically induced electric polarization in
Ba3Fe2O5Cl2 with tunable direction in three
dimensions
Phys. Rev. B, 101 180407(R) (2020)
A-181
C. Tan, et al.
Slow magnetic fluctuations and criticalslowing down in Sr2Ir1−xRhxO4
Phys. Rev. B, 101 195108 (2020)
A-182
S. Bao, et al.
Evidence for magnon-phonon coupling in
the topological magnet Cu3TeO6
Phys. Rev. B, 101 214419 (2020)
A-183
M. Soda, et al.
Magnetic correlations in YBaCo4O7 on
kagome and triangular lattices
Phys. Rev. B, 101 214444 (2020)
A-184
M. Hirschberger, et al.
High-field depinned phase and planar Hall
effect in the skyrmion host Gd2PdSi3
Phys. Rev. B, 101 220401(R) (2020)

A-189
J. Sugiyama, et al.
Nuclear magnetic field in Na0.7CoO2
detected with μ−SR
Phys. Rev. B, 102 144431 (2020)
A-190
H. Takahashi, et al.
Competing spin modulations in themagnetically frustrated semimetal EuCuSb
Phys. Rev. B, 102 174425 (2020)
A-191
C. Kim, et al.
Spin waves in the two-dimensional
honeycomb lattice XXZ-type van der Waals
antiferromagnet CoPS3
Phys. Rev. B, 102 184429 (2020)
A-192
D. Zhang, et al.
Temporally decoherent and spatiallycoherent vibrations in metal halide
perovskites
Phys. Rev. B, 102 224310 (2020)
A-193
H. Tamatsukuri, et al.
Magnetism induced by interlayer electrons
in the quasi-two-dimensional electride Y2C:
Inelastic neutron scattering study
Phys. Rev. B, 102 224406 (2020)
A-194
S. Uechi, et al.
Behavior of Sm in the boron cage of Smdoped RB6 (R =Yb, La) observed by multiplewavelength neutron holography
Phys. Rev. B, 102 54104 (2020)

A-175
Z. Cai, et al.
Spin dynamics of a magnetic Weyl semimetal
Sr1-xMn1-ySb2
Phys. Rev. B, 101 134408 (2020)

A-185
K. Iida, et al.
q=0 long-range magnetic order incentennialite CaCu3(OD)6Cl2 . 0.6D2O: A
spin-1/2 perfect kagome antiferromagnet
with J1−J2−Jd
Phys. Rev. B, 101 220408(R) (2020)

A-195
Y. Araki, et al.
Metamagnetic transitions andmagnetoelectric responses in the chiralpolar helimagnet Ni2InSbO6
Phys. Rev. B, 102 54409 (2020)

A-176
M. M. R. Bhuiyan, et al.
Spin order in the classical spin kagome
antiferromagnet MgxMn4−x(OH)6Cl2
Phys. Rev. B, 101 134424 (2020)

A-186
S. Gao, et al.
Crystal electric field excitations in thequantum spin liquid candidate NaErS2
Phys. Rev. B, 102 024424 (2020)

A-196
T. Yamamoto, et al.
Transverse asymmetry of γ rays fromneutron-induced compound states of 140La
Phys. Rev. C, 101 064624 (2020)

A-177
H. Ueda, et al.
Emergent spin-1 Haldane gap andferroelectricity in a frustrated spin-1/2 ladderPhys. Rev. B, 101 140408(R) (2020)

A-187
M. Fujita, et al.
Magnetic behavior of T’-type Eu2CuO4
revealed by muon spin rotation andrelaxation measurements
Phys. Rev. B, 102 045116 (2020)

A-197
H. Singh, et al.
Probing the adsorption of nonionic
micelles on different-sized nanoparticles by
scattering techniques
Phys. Rev. E, 102 62601 (2020)

A-188
N. Katayama, et al.
Robust atomic orbital in the cluster magnet
LiMoO2
Phys. Rev. B, 102 081106(R) (2020)

A-198
S. Allenspach, et al.
Multiple Magnetic Bilayers andUnconventional Criticality without
Frustration in BaCuSi2O6
Phys. Rev. Lett., 124 177205 (2020)

A-178
S. Asai, et al.
Helical and collinear spin density wave
order in the S=1/2 one-dimensional
frustrated chain compound NaCuMoO4(OH)investigated by neutron scattering
Phys. Rev. B, 101 144437 (2020)

J-PARC Annual Report 2020

Publications

85
A-199
K. Kuramochi, et al.
Synthesis and physical properties of the new
iridium oxyfluoride Sr2Ir(O,F)6-d using a
topochemical reaction method
Phys. Rev. Mater., 4 013403 (2020)
A-200
R. Takahama, et al.
Structural, magnetic, transport andthermoelectric properties of thepseudobrookite AlTi2O5-Ti3O5 system
Phys. Rev. Mater., 4 074401 (2020)
A-201
J. Guo, et al.
Magnetic-ﬁeld and composition tuned
antiferromagnetic instability in the quantum
spin-liquid candidate NaYbO2
Phys. Rev. Mater., 4 64410 (2020)
A-202
K. Nawa, et al.
Bound spinon excitations in the spin- 1/2
anisotropic triangular antiferromagnet
Ca3ReO5Cl2
Phys. Rev. Res., 2 043121(11pages) (2020)
A-203
S. Shamoto, et al.
Ultralow-energy magnon anomaly in yttrium
iron garnet
Phys. Rev. Res., 2 33235 (2020)
A-204
T. Nakajima, et al.
Crystallization of magnetic skyrmions in
MnSi investigated by neutron spin echo
spectroscopy
Phys. Rev. Res., 2 43393 (2020)
A-205
N. Kitamura, et al.
Local Structures in Disordered Rocksalt-Type
Li3NbO4- Based Positive Electrode Materials
for a Lithium-Ion Battery
Phys. Status Solidi. B Basic Solid State Phys.,
257 2000112-1-7 (2020)
A-206
Y. Sakaguchi, et al.
Excitation Light Energy Dependence of Silver
Photodiffusion into Amorphous Germanium
Sulfide: Neutron and X-Ray Reflectivity and
X-Ray Diffraction
Phys. Status Solidi. B Basic Solid State Phys.,
257 2000178 (2020)

Development of a bunch-width monitor for
low-intensity muon beam below a few MeV
Physical Review Accelerators and Beams, 23022804 (2020).

The anomalous magnetic moment of themuon in the Standard Model
Physics Reports-Review Section of Physics
Letters 887 (2020) 1

A-209
T. Yamaga, et al.
Observation of a KNN bound state in the 3He(K-, Λp)n reaction
Physical Review C 102 (2020) 44002

A-219
Y. Kimura, et al.
Folded amphiphilic homopolymer micelles
in water: uniform self-assembly beyond
amphiphilic random copolymers
Polym. Chem., 11 5156 (2020)

A-210
K. Abe, et al.
First combined measurement of the muon
neutrino and antineutrino charged-current
cross section without pions in the final stateat T2K
Physical Review D 101 (2020) 112001
A-211
K. Abe, et al.
Simultaneous measurement of the muon
neutrino charged-current cross section on
oxygen and carbon without pions in the final
state at T2K
Physical Review D 101 (2020) 112004
A-212
K. Abe, et al.
Measurement of the muon neutrino
charged-current single π+ production onhydrocarbon using the T2K off-axis neardetector ND280
Physical Review D 101 (2020) 12007
A-213
W. Foreman, et al.
Calorimetry for low-energy electrons using
charge and light in liquid argon
Physical Review D 1010(2020) 12010
A-214
K. Abe, et al.
First measurement of the charged current νμdouble differential cross section on a watertarget without pions in the final statePhysical Review D 102 (2020) 12007
A-215
N. Shimizu, et al.
First search for KL → π0γ
Physical Review D 102 (2020) 51103
A-216
K. Abe, et al.
Search for Electron Antineutrino Appearance
in a Long-Baseline Muon Antineutrino Beam
Physical Review Letters 124 (2020) 161802

A-207
H. Saitoh, et al.
Neutron diffraction study on the deuterium
composition of nickel deuteride at hightemperatures and high pressures
Physica B Condens. Matter., 587 412153 (2020)

A-217
T. Kitahara, et al.
New Physics Implications of Recent Search
for KL → π0νν at KOTO
Physical Review Letters 124 (2020) 71801

A-208
Y. Sue, et al.

A-218
Tatsumi AOYAMA, et al.

A-220
D. Ito, et al.
efficient synthesis to crystallinity control
Polym. Chem., 11 5181 (2020)
A-221
K. A. Suyama, et al.
Fine-structure analysis ofperhydropolysilazane-derived nano layers
in deep-buried condition using polarized
neutron reflectometry
Polymers, 12 2180 (2020)
A-222
H. Natori
Development of very slow negative muonbeam
PoS (NuFACT2019), 369 090 (2020)
A-223
S. Makimura, et al.
Status and Future Prospect of Muon Target
at J-PARC MLF
PoS (NuFACT2019), 369 124 (2020)
A-224
R.Abramishvili, et al.
COMET Phase-I technical design report
Prog. Theor. Exp. Phys., 033C01- (2020)
A-225
J. Beare, et al.
Study of muonium emission from laserablated silica aerogel
Prog. Theor. Exp. Phys., 2020 123C01 (2020)
A-226
K. Hirota, et al.
Neutron lifetime measurement with pulsed
cold neutrons
Prog. Theor. Exp. Phys., 2020 123C02 (2020)
A-227
H. Ohnishi, et al.
Hadron Physics at J-PARC
Progress in Particle and Nuclear Physics 113(2020) 103773
A-228
Y. Ichikawa, et al.
An event excess observed in the deeply
bound region of the 12C(K^-,p) missing
mass spectrum
Prog. Theor. Exp. Phys., 123D001 (2020)

Publications

J-PARC Annual Report 2020

86
A-229
T. Tanaka, et al.
Gamma-ray spectra from thermal neutron
capture on gadolinium-155 and natural
gadolinium
Prog. Theor. Exp. Phys., 2020 043D02 (2020)
A-230
O. Takahashi, et al.
Microstructural Features and Ductile-Brittle
Transition Behavior in Hot-Rolled Lean
Duplex Stainless Steels
Quantum Beam Science, 4 16 (2020)
A-231
Y. WangPhase Stress Measurement of Centrifugally
Cast Duplex Stainless Steel by Neutron
Diffraction
Quantum Beam Science, 4 28 (2020)

A-238
T. MIBE
Anomalous Magnetic Moment and Electric
Dipole Moment of Muon
Radioisotopes 69 (2020)n 145
A-239
T. Shinohara, et al.
The energy-resolved neutron imaging
system, RADEN
Rev. Sci. Instrum., 91 043302 (2020)
A-240
V. Sonnenschein, et al.
An experimental setup for creating andimaging 4He2∗ excimer cluster tracers
in superfluid Helium-4 via neutron-3He
absorption reaction
Rev. Sci. Instrum., 91 33318 (2020)

A-232
Y. Noda, et al.
The Large-Area Detector for Small-Angle
Neutron Scattering on iMATERIA at J-PARC
Quantum Beam Science, 4 32 (2020)

A-241
M. Wada, et a.
Measurement of a time dependent spatial
beam profile of an RF-driven H- ion source
Rev. Sci. Instrum., Vol 91, 013330-1 - 013330-5(2020)A-233
Y. Noda, et al.
First Experiment of Spin Contrast Variation
Small-Angle Neutron Scattering on theiMATERIA Instrument at J-PARC
Quantum Beam Science, 4 33 (2020)

A-242
K. Arai, et al.
Reconsideration of the conformation of
methyl cellulose and hydroxypropyl methyl
cellulose ethers in aqueous solution
RSC Adv., 10 19059 (2020)

A-234
K. Nakagawa, et al.
Characterization of Dislocation
Rearrangement in FCC Metals during Work
Hardening Using X-ray Diffraction LineProfile Analysis
Quantum Beam Science, 4 36 (2020)

A-243
M. Naeem, et al.
Cooperative deformation in high-entropy
alloys at ultralow temperatures
Sci. Adv., 6 eaax4002 (2020)

A-235
S. Koizumi, et al.
Advanced Small-Angle Scattering
Instrument Available in the Tokyo Area.
Time-of-Flight, Small-Angle Neutron
Scattering Developed on the iMATERIA Di
ractometer at the High Intensity Pulsed
Neutron Source J-PARC
Quantum Beam Science, 4 42 (2020)
A-236
Y. Onuki, S. SatoIn Situ Observation for DeformationInduced Martensite Transformation (DIMT)
during Tensile Deformation of 304 StainlessSteel Using Neutron Diffraction. PART I:
Mechanical Response
Quantum Beam Science, 4 44227 (2020)
A-237
A. Momose, et al.
Recent Progress in X-ray and Neutron Phase
Imaging with Gratings
Quantum Beam Science, 4 9 (2020)

A-244
S. Sato, et al.
Antiferromagnetism in perfectly ordered
L10-MnAl with stoichiometric composition
and its mechanism
Sci. Rep., 10 12489 (2020)
A-245
S. Yamamoto, et al.
Optical imaging of muonsSci. Rep., 10 20790 (2020)
A-246
R. Inoue, et al.
Dynamics of proteins with different
molecular structures under solution
condition
Sci. Rep., 10 21678 (2020)
A-247
W. Woo, et al.
Stacking Fault Energy Analyses of Additively
Manufactured Stainless Steel 316L and
CrCoNi Medium Entropy Alloy Using In Situ
Neutron Diffraction
Sci. Rep., 10 43845 (2020)

A-248
Y. K. Kshetri, et al.
Electronic structure, thermodynamic stability
and high temperature sensing properties of
Er-α-SiAlON ceramics
Sci. Rep., 10 4952 (2020)
A-249
H. Saitoh, et al.
Crystal and Magnetic Structures of Double
Hexagonal Close-Packed Iron DeuterideSci. Rep., 10 9934 (2020)
A-250
E. Shoji, et al.
Neutron computed tomography of phaseseparation structures in solidified CuCo
alloys and investigation of relationshipbetween the structures and melt convection
during solidification
Scr. Mater., 175 29 (2020)
A-251
K. Cho, et al.
Study on formation mechanism of {332} <113 > deformation twinning in metastable
β-type Ti alloy focusing on stress-induced
α”martensite phase
Scr. Mater., 177 106-111 (2020)
A-252
T. Yamashita, et al.
Role of retained austenite in low alloy steel
at low temperature monitored by neutron
diffraction
Scr. Mater., 177 43992 (2020).
A-253
Z. Deng, et al.
Elinvar property of cold-rolled NiTi alloy
Scr. Mater., 187 197-201 (2020)
A-254
M. Naeem, et al.
Extremely high dislocation density anddeformation pathway of CrMnFeCoNi highentropy alloy at ultralow temperature
Scr. Mater., 188 21-25 (2020)
A-255
N. Ishida, et al.
Synthesis, cathode property and crystal,electronic and local structures of Mg2Mo3O8
as Mg rechargeable battery cathode material
Solid State Ion., 354 115413 (2020)
A-256
R. Li, et al.
Anomalous sub-diffusion of water inbiosystems: From hydrated protein powders
to concentrated protein solution to living
cells
Struct. Dyn., 7 054703 (2020)
A-257
J. Kim, et al.
Pyroelectric power generation from the

J-PARC Annual Report 2020

Publications

87
waste heat of automotive exhaust gas
Sustain. Energy Fuels, 4 1143 (2020)
A-258
Y. Hosoya, et al.
Mechanism of improved ductility of 1,500
MPa-class ultra-high strength cold-rolled
steel sheet produced by rolling andpartitioning method
Tetsu to Hagane, 106 154-164 (2020)
A-259
Y. Tomota, et al.
In situ Neutron Diffraction on Ferrite andPearlite Transformations for a 1.5Mn-1.5Si0.2C Steel
Tetsu to Hagane, 106 262-271 (2020)

A-260
Y. Onuki, et al.
Mutual Verification of Phase Fraction
Analysis Techniques for Steels Comprising
Deformation Induced Martensite Phases:
Neutron-Diffraction-Based Rietveld Texture
Analysis and Saturation Magnetization
Measurement
Tetsu to Hagane, 106 457 (2020)

A-262
Y. Sakaguchi, K. Tamura
Photo-induced effects on amorphous andliquid selenium by pulsed laser illumination-Photo-induced structural changes in a
network of selenium chains
Z. Phys. Chem., 235 189-212 (2020)

A-261
Y. Sakaguchi, et al.
Silver photodiffusion into amorphous Ge
chalcogenides - Excitation photon energy
dependence of the kinetics probed byneutron reflectivity
The European Physical Journal Applied Physics,
90 30101 (2020)

Conference Reports and Books
B-001
S. Meigo, et al.
Measurement of displacement cross section
with the kinematic energy above 400
MeV for structural materials in the proton
accelerator facilities
JPS Conf. Proc. 28, 061004
B-002
F. Sakuma, et al.
K- pp bound system at J-PARC
AIP Conference Proceedings 2249 (2020) 20005
B-003
A. Kimura, et al.
Neutron capture and total cross-section
measurements of 155Gd and 157Gd at
ANNRI in J-PARC
EPJ Web Conf., 239 1012 (2020)
B-004
G. Rovira, et al.
Measurement of the neutron capture crosssection of 237Np using ANNRI at MLF/J-PARC
EPJ Web Conf., 239 1017 (2020)

A comprehensive study of spallation models
for proton-induced spallation products
yields utilized in transport calculation
EPJ Web of Conferences 239, 06001
B-008
H. Matsuda, et al.
Measurement of nuclide production crosssection for lead and bismuth with proton inenergy range from 0.4 GeV to 3.0 GeV
EPJ Web of Conferences 239, 06004
B-009
S. Meigo, et al.
Measurement of displacement cross sectionin J-PARC for proton in the energy range
from 0.4 GeV to 3 GeV
EPJ Web of Conferences 239, 06006
B-010
Y. Iwamoto, et al.
Calculation of athermal recombination
corrected dpa cross sections for proton,
deuteron and heavy-ion irradiations using
the PHITS code
EPJ Web of Conferences 239, 20011

B-005
T. Katabuchi, et al.
Fast Neutron Capture Reaction Data
Measurement of Minor Actinides forDevelopment of Nuclear Transmutation
Systems
EPJ Web Conf., 239 1044 (2020)

B-011
M. Yoshimoto, et al.
Progress status in fabrication of HBC stripper
foil for 3-GeV RCS at J-PARC in Tokai site
EPJ Web of Conferences, 229(2020), p.01001_1- 01001_7

B-006
S. Iwamoto, et al.
Evaluation of gamma-ray strength function
based on measured gamma-ray pulse-heightspectra in time-of-flight neutron captureexperiments
EPJ Web Conf., 239 17016 (2020)

B-012
S. Abe, et al.
Impact of Hydrided and Non-Hydrided
Materials Near Transistors on NeutronInduced Single Event UpsetsIEEE International Reliability Physics
Symposium Proceedings, (2020)

B-007
H. Iwamoto, et al.

B-013
T. Okamura, et al.

Helium Transfer Line with ConductionCooled Nb-Ti Superconducting Wires for
COMET Muon Transport Solenoid
IOP Conf. Ser. Mater. Sci. Eng., 755 (2020),
12058
B-014
T. Okamura, et al.
Helium Transfer Line with ConductionCooled Nb-Ti Superconducting Wires for
COMET Muon Transport Solenoid
IOP Conference Series Materials Science andEngineering 755 (2020) 12058
B-015
T. MibePrecise Measurement of Anomalous
Magnetic Moment of Muon
Journal of Computer Chemistry, Japan 19(2020) 64
B-016
H. Hotchi, et al.
J-PARC 3-GeV RCS; 1-MW beam operation
and beyond
Journal of Instrumentation (Internet), 15(7),p.P07022_1 - P07022_16, 2020/07
B-017
A. Nakamura, et al.
R&D on the gas injection system of Beam
Induced Fluorescence Monitor toward MW
beam power at the J-PARC Neutrino Beamline
Journal of Physics: Conference Series 1468
(2020) 12213
B-018
T. Nomura
A future K0L → π0νν experiment at J-PARC
Journal of Physics: Conference Series 1526
(2020) 12027

Publications

J-PARC Annual Report 2020

88
B-019
T Onji, et al.
Superconducting Properties of a Prototype
Pancake Coil using a MgB2 Rutherford-type
Stranded Conductor
Journal of Physics: Conference Series 1559
(2020) 12057
B-020
M Hira, et al.
Theoretical and experimental investigationof R&W and W&R SMES coils woundwith large-scale MgB2 Rutherford
cables operated around liquid hydrogentemperature
Journal of Physics: Conference Series 1590
(2020) 12058
B-021
K. Tanaka
Major Accelerator Facilities for Nuclear
Physics in Asia Pacific
Journal of Physics: Conference Series 1643
(2020) 12041
B-022
T. Gogami, et al.
Study on the baryon interaction by Ξ
hypernuclear spectroscopy with the (K-, K+)
reaction
Journal of Physics: Conference Series 1643
(2020) 12133
B-023
K. Miwa, et al.
Study of ∑N interaction from the ∑pscattering experiment at J-PARC
Journal of Physics: Conference Series 1643
(2020) 12174
B-024
S. Kumano
Tensor-polarized structure functions: Tensor
structure of deuteron in 2020's
Journal of Physics: Conference Series 543(2020) 12001
B-025
Y. Iwamoto, et al.
Measurement of defect induced electricalresistivity change of tungsten wire atcryogenic temperature using high energy
proton irradiation
JPS Conf. Proc. 28, 061003
B-026
S. Saito, et al.
Current Status of R&D and PIE Program for
ADS Material Development in JAEAJPS Conf. Proc. 28, p.071003_1 - 071003_6,
2020/02
B-027
S. Makimura, et al.
Feasibility Study for NITE SiC/SiC as theTarget Material for Pions/Muons Production
at High-Power Proton Accelerator Facilities

JPS Conf. Proc., 28 031005 (2020)

COMET Experiment
Meson, 52 (2020), 20

B-028
T. Naoe, et al.
Change in Mechanical Properties by HighCycle Loading Up to Gigacycle for 316L
Stainless SteelJPS Conf. Proc., 28 061009 (2020)

B-038
Ken-ichi SASAKI
Precise Magnetic Field Shimming and
Absolute Magnetic Field Measurement
Meson, 52 (2020), 24

B-029
N. Nakamura, et al.
μSR and Neutron Scattering Studied on
Possible Partially-Disordered Magnetic State
Coexisting with Heavy Quasiparticles in
SmPt2Si2
JPS Conf. Proc., 29 012009 (2020)

B-039
T. Asami, et al.
DEVELOPMENT OF REAL-TIME COD
CORRECTION SYSTEM FOR THE HIGHINTENSITY PROTON SYNCHROTRONS
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 20- (2020)

B-030
N. Metoki, et al.
The f-electron State of the Heavy Fermion
Superconductor NpPd5Al2 and the
Isostructural Family
JPS Conf. Proc., 30 011123 (2020)

B-040
K. Kadowaki, et al.
THE DESIGN OF THE NEW BEAM DUMP FOR
J-PARC MR UPGRADE
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 205- (2020)

B-031
S. Nakazato, et al.
Successive Phase Transitions in R3Ir4Sn13 (R:La and Ce) Investigated Using Neutron and
X-ray Diffraction
JPS Conf. Proc., 30 011128 (2020)

B-041
T. Shibata, et al.
THE NEW HIGH-FIELD SEPTUM MAGNET FOR
UPGRADING OF FAST EXTRACTION IN MR
J-PARC(2)Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 388- (2020)

B-032
K. Iba, et al.
Magnetic Structure of a Chiral Magnet
DyNi3Al9JPS Conf. Proc., 30 011164 (2020)
B-033
D. Hirai, et al.
Muon Spin Rotation, High-Field
Magnetization, and Structural Study ona Spin–Orbit-Entangled Mott Insulator
Ba2MgReO6
JPS Conf. Proc., 30 11143 (2020)
B-034
S. Tsunoda, et al.
μSR study of the magnetic state in hole andelectron doped Sr2IrO4
JPS Conf. Proc., 30 11145 (2020)
B-035
K. A. Suyama, et al.
Metal catalyzed H-D exchange methods
using D2O as a deuterium source: A
comparative study in different sealed
devices
JPS Conf. Proc., 33 011150 (2020)
B-036
C. OhmoriImprovements of Beam Acceleration
Systems and μSR
Meson
B-037
Makoto Yoshida

B-042
Y. Komatsu, et al.
BEAM COMMISSIONING OF A NEW PRIMARYPROTON BEAM LINE AT J-PARC HADRONEXPERIMENTAL FACILITY
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 485- (2020)
B-043
M. Furusawa, et al.
REPLACEMENT AND UPGRADE OF RF POWER
SUPPLY CONTROL DEVICES IN J-PARC
SYNCHROTRONS
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 521- (2020)
B-044
M. Yang, et al.
UPGRADED RADIATION DOSE MONITORSYSTEM WITH XBEE DISPATCHER PROGRAM
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 524- (2020)
B-045
T. Shibata, et al.
THE NEW LOW-FIELD SEPTUM MAGNET FOR
UPGRADING OF FAST EXTRACTION IN MR
J-PARC(6)Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 594- (2020)
B-046
K. SATO, et al.
LONG-TERM ELECTRICITY POWERCONSUMPTION TRENDS AT J-PARC

J-PARC Annual Report 2020

Publications

89
ACCELERATOR FACILITIES
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 620- (2020)
B-047
M. Nomura, et al.
APPLYING IMAGE RECOGNITIONTECHNOLOGY BY CONVOLUTIONAL NEURALNETWORKS TO MOUNTAIN PLOT IMAGES
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 64- (2020)
B-048
M. Tomizawa, et al.
DESIGN AND STATUS OF CURRENT BEAM
DUMP SYSTEM IN J-PARC MAIN RING
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 665- (2020)
B-049
H. Okita, et al.
BENCHMARKING OF LONGITUDINALCALCULATION CODE BLOND FOR
APPLICATION TO J-PARC RCS
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 674- (2020)
B-050
F. Tamura, et al.
TOWARDS WIDESPREAD USE OF MTCA IN
ACCELERATORS
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 68- (2020)
B-051
A. Kobayashi, et al.
STUDY OF THE TRANSVERSE BEAMINSTABILITY CAUSED BY THE RESISTIVE-WALL
IMPEDANCE AT THE J-PARC MAIN RING
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 684- (2020)
B-052
T. Toyama, et al.
ANALYSIS OF COLLECTIVE INSTABILITIES OFUNEVEN FILLED BEAMS INCLUDING LONG
RANGE WAKE FIELDS USING AN IIR FILTER
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 689- (2020)
B-053
T. Shibata, et al.
THE REDUCTION OF THE LEAKAGE FIELD OF
THE NEW INJECTION SEPTUM MAGNET 1
BY USING A NEW MAGNETIC SHIELD IN MR
J-PARC
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 793- (2020)
B-054
T. Sugimoto, et al.
PERFORMANCE OF NEW TERMINATIONRESISTORS OF J-PARC MAIN RING INJECTION
KICKER MAGNET
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 798- (2020)

B-055
M. Shirakata
PROTOTYPE OF SIX-AXIS MOUNT FOR QSCMAGNET IN BEAM COLLIMATOR AREA
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 802- (2020)
B-056
Y. Kawabata, et al.
CONSTRUCTION OF DISASTER PREVENTIONSYSTEM BY DEDICATED NETWORK DEVICES
AND MOBILE APPLICATION IN J-PARC MR
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 845- (2020)
B-057
T. SHIMOGAWA, et al.
STATUS OF NONDESTRUCTIVE DEVICEDEVELOPMENT FOR SLOW EXTRACTION
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 875- (2020)
B-058
H. Yamaguchi, et al.
FEASIBILITY STUDY ON DOSIMETRY USINGALANINE DOSIMETER AROUND HIGHINTENSITY PROTON ACCELERATOR
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), 93- (2020)
B-059
Y. SATO, et al.
Operation of a new multi-ribbon beamprofile monitor in the beam abort line of
J-PARC main ring
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), FRPP17- (2020)
B-060
Y. HASHIMOTO, et al.
Development of a wide dynamic-range
beam-profile monitor using OTR andfluorescence for Injected beams in J-PARC
Main Ring
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), FRPP19- (2020)
B-061
N. KAMIKUBOTA, et al.
Twelve-year operation and upgrade
experiances of J-PARC MR control
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), WEOOP04- (2020)
B-062
K. Noguchi, et al.
Improvement of proton beam extinction
and optimization of the compensation kicker
magnet of J-PARC main ring for the COMET
experimentProc. 17th Ann. Mtg. Part. Accel. Soc. Jpn.
(Internet), WEOT02- (2020)
B-063
B. Yee-Rendon, et al.
Error studies for the JAEA-ADS linac
Proc. 17th Ann. Mtg. Part. Accel. Soc. Jpn. (2020

), 33
B-064
M. Sugita, et al.
PRECISE OPERATION OF SUPERCONDUCTINGMAGNET FOR BEAM CAPTURE APPLYING
WHOLE-BODY MRI MAGNET TECHNOLOGY
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 13 (2020)
B-065
F. Muto, et al.
BEAM PROFILE MEASUREMENT SYSTEM IN
THE NEIGHBORHOOD OF THE J-PARC HIGHMOMENTUM BEAMLINE TARGET
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 130 (2020)
B-066
S. Makimura, et al.
PRESENT STATUS OF COMET TARGET AT
J-PARC
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 150 (2020)
B-067
Y. Nakazawa, et al.
CURRENT STATUS FOR HIGH-POWER TESTSOF AN APF IH-DTL PROTOTYPE IN THE MUON
LINAC
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 154 (2020)
B-068
H. Yasuda, et al.
SPIN DYNAMICS SIMULATION IN MUONACCELERATOR
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 173 (2020)
B-069
Y. Nakazawa, et al.
DEVELOPMENT OF A DIAGNOSTIC BEAMLINEFOR THE DEMONSTRATION OF THE MUONACCELERATION WITH AN APF IH-DTL
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 254 (2020)
B-070
H. Hirayama, et al.
THE STATUS REPORT OF DEMONSTRATIVE
EXPERIMENT OF 3D SPIRAL BEAM INJECTION
FOR J-PARC MUON G-2/EDM EXPERIMENT
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 29 (2020)
B-071
R. Kurasaki, et al.
DEVELOPMENT OF A ROTATING-DISC TYPETARGET FOR J-PARC HADRON BEAMLINE (2)Proc. Ann. Mtg Part. Accel. Soc. Jpn. 402 (2020)
B-072
Y. Komatsu, et al.
BEAM COMMISSIONING OF A NEW PRIMARYPROTON BEAM LINE AT J-PARC HADRONEXPERIMENTAL FACILITY
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 485 (2020)
B-073
H. Takahashi, et al.
DEVELOPMENT OF NEW RADIATIONRESISTANT MAGNETS USING CYANATE ESTERRESIN

Publications

J-PARC Annual Report 2020

90
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 599 (2020)
B-074
H. Watanabe, et al.
DEVELOPMENT OF A BELLOWS DUCT WITH A
SEMI-REMOTE HANDLING SYSTEM AT J-PARC
HADRON FACILITY
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 786(20209)B-075
M. Abe, et al.
TRIAL DESIGN OF A STEERING MAGNET TO
BE PLACED IN MUON STORAGE MAGNET FOR
G-2/EDM PRECISION MEASUREMENT
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 807 (2020)
B-076
M. Saito, et al.
OPERATION STATUS AND ANALYSIS OF
THE NEW PRODUCTION TARGET AT J-PARC
HADRON EXPERIMENTAL FACILITY
Proc. Ann. Mtg Part. Accel. Soc. Jpn. 822 (2020)
B-077
S. Makimura, et al.
Development of Toughened Fine-Grained
Recrystallized Tungsten for high-heat-load
device in accelerators
Proc. Ann. Mtg Part. Accel. Soc. Jpn. HGKP04(2020)
B-078
K. Noguchi, et al.
Improvement of proton beam extinction
and optimization of the compensation kicker
magnet of J-PARC main ring for the COMET
experimentProc. Ann. Mtg Part. Accel. Soc. Jpn. WEOT02(2020)B-079
S. V. Cao, M. L. Friend
INVESTIGATION OF AN OPTICAL-FIBERBASED BEAM LOSS MONITOR AT THE J-PARC
EXTRACTION NEUTRINO BEAMLINE
Proc. IBIC 119 (2020)
B-080
S. V. Cao, et al.
FIRST BEAM PROFILE MEASUREMENTS BY
BEAM INDUCED FLUORESCENCE AT THE
J-PARC NEUTRINO EXTRACTION BEAMLINE
Proc. IBIC 184 (2020)
B-081
T. Murakawa, et al.
Neutron crystallography of copper amineoxidase reveals keto/enolate interconversionof the quinone cofactor and unusual proton
sharing
Proc. Natl. Acad. Sci. U. S. A., 117 10818-10824(2020)B-082
Y. Fukuda, et al.
High-resolution neutron crystallography

visualizes an OH-bound resting state of acopper-containing nitrite reductase
Proc. Natl. Acad. Sci. U. S. A., 117 4071-4077(2020)B-083
K. Komatsu, et al.
Anomalous hydrogen dynamics of the ice
VII-VIII transition revealed by high-pressure
neutron scattering
Proc. Natl. Acad. Sci. U. S. A., 117 6356-6361(2020)B-084
K. Yanai, et al.
Beam measurement of medium energy
beam transport line (MEBT1) to improve
injection beam matching in J-PARC linac DTL
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 127129 (2020)
B-085
Y. Nakazawa, et al.
Current status for high-power tests of an APF
IH-DTL prototype in the muon LINAC
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 154157 (2020)
B-086
Y. Takeuchi, et al.
Development of Disk-and-Washer cavity formuon linear accelerator
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 158162 (2020)
B-087
H. Yasuda, et al.
Spin Dynamics Simulation in the Muon
Accelerator
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 173176 (2020)
B-088
M. Otani, et al.
Study of Muon Acceleration by Autoresonance Cyclotron
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 202204 (2020)
B-089
Y. Kondo, et al.
Conceptual design of a L-band linac formuon acceleration
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 218221 (2020)
B-090
R. Kitamura, et al.
Evaluation of the bunch-shape monitor forthe high-intensity proton beamProc. of 17th Annual Meeting of Particle

Accelerator Society of Japan (Internet), 251253 (2020)
B-091
Y. Nakazawa, et al.
Development of a diagnostic beamline forthe demonstration of the muon acceleration
with an APF IH-DTL
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan (Internet), 254257 (2020)
B-092
Y. Fuwa, et al.
Analysis on Voltage Droop on J-PARC
Klystron High Voltage Power Supply
Proc. of 17th annual Meeting of Particle
Accelerator Society of Japan (internet), 780782 (2020)
B-093
H. Takahashi, et al.
MACHINE STATUS MONITORING SYSTEM FOR
J-PARC RCS
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 275-279 (2020).
B-094
P. K. Saha, et al.
Status of the proof-of-principle
demonstration of 400 MeV H- laser strippingat J-PARC
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 436-440 (2020).
B-095
H. Harada, et al.
Status of laser development for laser
stripping experiment at J-PARC
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 441-445 (2020).
B-096
K. Okabe
CHARGE EXCHANGE METHOD OF H- BEAM
BY ELECTRON BEAM
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 446-448 (2020).
B-097
N. Hayashi
Intensity dependence of the beam current
monitors at J-PARC RCS
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 478-481 (2020).
B-098
A. Kobayashi, et al.
Study of the transverse beam instability
caused by the resistive-wall impedance at
the J-PARC main ring
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 684-688 (2020).
B-099
T. Toyama, et al.
Analysis of collective instabilities of uneven

J-PARC Annual Report 2020

Publications

91
filled beams including long range wakefields using an IIR filter
Proc. of the 17th Annual Meeting of Particle
Accelerator Society of Japan, 689-692 (2020).
B-100
K. Yamamoto, et al.
Results of 1-MW Operation in J-PARC 3 GeV
Rapid Cycling Synchrotron
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 209 - 213
B-101
T. Takayanagi, et al.
Semiconductor switch power supply for RCS
kicker
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 25 - 28
B-102
H. Harada, et al.
Status of laser development for laser
stripping experiment at J-PAR
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 441 - 445

KEK Reports
C-001
Safety Division, J-PARC Center
Annual Report on the Activities of Safety in
J-PARC, FY2019
KEK Internal 2020-6

JAEA Reports
D-001
Safety Division, J-PARC Center
Annual Report on the Activities of Safety in
J-PARC, FY2019
JAEA-Review 2020-067(2020)

OthersE-001
T. Nakadaira
Recent Progress of Neutrino Oscillation
Experiments at J-PARC
Kasokuki, 17 (2020) 174

B-103
S. Hatakeyama, et al.
High voltage dependence measurement ofbeam loss monitor in J-PARC RCS
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 475 - 477

B-107
F. Tamura, et al.
Towards widespread use of MTCA inaccelerators
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 68 - 72

B-104
A. Ono, et al.
Development of ignitron alternative
semiconductor switch and new kicker power
supply for J-PARC accelerator
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 590 - 593

B-108
K. Moriyama, T. Nakatani
Public cloud-based remote accessinfrastructure for neutron scatteringexperiments at MLF, J-PARC
Proc. of the 17th International Conference on
Accelerator and Large Experimental Physics
Control Systems, 707-713 (2020)

B-105
M. Nomura, et al.
Applying image recognition technology by
convolutional neural networks to mountainplot images
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 64 - 67
B-106
H. Okita, et al.
Benchmarking of Longitudinal Calculation
Code BLOND for Application to J-PARC RCS
Proc. of 17th Annual Meeting of Particle
Accelerator Society of Japan, (2020), 674 - 678

B-109
A. UenoJ-PARC 𝐇− ion source and space-charge
neutralized LEBT for 100-mA high energy
and high duty factor LINACs
Review of Scientific Instruments 91, 033312(2020)

J-PARC Annual Report 2020
Vol.1: Highlight© J-PARC Center
December 2021

Japan Proton Accelerator Research Complex

High Energy Accelerator Research Organization (KEK)
Japan Atomic Energy Agency (JAEA)

IbarakiTokai

J-PARCJR Joban L ine

Mito
Mt.Tsukuba

Pacific OceanTokyo

Narita

Ueno
Tokyo

0

20

40km

2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan

http://j-parc.jp/

J-PARC 21-01